I got the interior surfaces all smoothed, cleaned and ready to paint.  But, before painting, I designed and constructed as much of the partitions and rooms as I could.  (get a new #11 blade).  I didn't worry about all the detail in the rooms at this point, but constructed the outside walls, cut out the doors, etc.  I worked on getting a good fit and how everything would attach in there. 

I also made as many patterns/templates of the walls that I could.  These would be used later to cut out the finished overlays (if your like me, you have a lot of clear styrene laying around that's been scratched too much to use for glazing the windows - this is a good place to use it - more later on making the finished overlays).  I cut some .010in styrene sheet into pieces, fitted and trimmed until each piece covered the particular wall area that I was working on.  For those pieces that include windows, I held the piece in place on the inside, or taped it down in position if there was room, and scribed out the windows from the outside.  I used the scribes; a blade can scrape the inner edges of the windows.  Then I cut out the windows (get a new blade), test fitted, trimmed, started over until I was satisfied with the fit of each piece and how they lined up with each other.  In coach, lounge or dinner areas where there are curtains or other window dressings, I just made a strip for the wall area above and a strip for the area below the windows.  I covered the area between windows later with the curtains or window dressings.  I spent a lot of hours making and remaking those templates, so I stored them somewhere safe for later.

I cleaned the inside surfaces again, and painted the wall areas the color that I wanted to show as a thin outline around the windows, or as a floorboard or other detail.  I did the dome obs walls in steel.  The ceiling I did in cream (the color of the ceiling will have some effect on the over all color of the interior light and the final effect).

To paint the inside of the side pieces on the Walthers cars, without screwing up the outside paint job, including the inner edges of the windows, I stuffed some Play-Doh through the window openings from the outside.  Then I shaped the doh on the inside with a tooth pick to get the inner window edges masked without covering the inside wall surface. The doh cleans off easily.

While the inside is curing (min 4 days to be able to withstand masking - more the safer), I had the partitions/rooms to paint and detail.  I also had some overlay sheets to design and print out on the computer, curtains to make, chairs, flooring, research.........  

Ok.  The interior surface paint has been applied and is cured.  I cut small strips of copper tape and used them to make the electrical runs back, forth and around the car.  Since the brass conducts, I put down strips of Scotch Super tape (packing tape) first, and then laid down the copper on top of it.  I ended up with less than .005in build up.  That's small enough to overlay without bulges.  I got strips running behind wall panels/overlays, under carpeting, and it makes good contact points. Obviously, electrical insulation is not necessary on the plastic stuff.  But, keep in mind that you have to heat up that copper to solder.  Too much heat and too long of an exposure will warp and melt the plastic.  That is REAL bad!  The layer of packing tape will help, but this is where a variable temperature soldering station comes in handy.  Set it as low as possible, and still be able to flow the solder.  I strongly suggest practicing on a junk car to get the technique down. If one has the head room, putting .060 styrene strips under the CU tape is much safer.

I made 2 light rails to run across the ceiling from end to end using .060 or .080 styrene strips and the copper tape.  At the spots where I glued the rails down, I scratched off the paint down to the bare surface.  I set the rails down at masking tape width.

(See Lighting and Electrical for pics and more info)

It's hard to imagine how I would make skinny little fake wood paneling, tiny little pictures and signs on the wall or a decal without a computer.  I find just about every pattern or picture I want on the net.  All the paint, capture and image manipulation software, plus the print technology make the computer a very creative tool for a modeler.  I think everyone here has caught on to that.  When shrinking an image, I resample at a higher resolution.  Normally, 600 dpi works.  I clear coat the printed sheets of photo paper with Krylon Crystal Clear Satin. The paper should last a long time and shouldn't fade or yellow.  Colors will darken, so I allow for that.  Using the wall templates I made earlier, I cut out the overlays (get a new blade, and often) from the printed sheets.  When I'm satisfied that the finish overlay or picture/sign is good enough and fits in there, I clear coat it lightly again to get all the edges.

When working with fabric for carpeting or the chair guard panels under coach windows, I back the fabric with the clear packing tape.  It helps minimize fraying, holds the shape and the glue doesn't seep through.  For different pile, patterns or to alter the color a little, I airbrush Dulcote and/or paint.

Making curtains and drapes out of fabric is somewhat tedious. I cut about 3in wide by 6in long strips of the fabric I want to use.  I lay down a strip, backside up, on a sheet of plastic.  Starting at one end, I fold back about 1/2in to make a crease across the strip.  I open the fold back up and spread a fair amount of Testor Clear Parts Cement and Window Maker in the crease and about 1/4in to each side of it, fold the fabric back over and press it down.  I use just enough of the glue to slightly soak through the fabric.  It dries clear.  I cut the folded piece about an inch from the end, and continue down the strip, making a bunch of single folds in the same manner. After the glue sets, I cut the folds off (get a new blade, and often) with a straight edge about .040in from the end of the fold.  By varying this dimension, I get curtains of different thickness.  I then glue, using small amounts of CA glue, the .040in strips on top of each other till I get the width of curtain I want. My 2x2 wood block with a strip of tape, sticky side up, comes in handy here for laying out and holding the strips.  If I want a curtain that looks partly drawn open, I glue thicker folded strips on edge between the tight folds.  After the CA glue sets, I cut curtains to desired length.

I start assembling with glazing the windows.  I cut .005 or .010in strips of clear styrene long enough to cover as many windows in an area as possible, and then glue them down.  This is one reason why I like brass.  The walls are thin, and the glazing, shades and wall overlays end up giving a thicker, more real appearance, and the windows look flush.  Next I build up the area around the glazing with scrap styrene to keep the wall surface flat for mounting the shades and overlays.  I make my shades out of scrap .005in styrene, and taller than the window so I can glue them down above the window.  It's a lot easier and cleaner than gluing them to the window pane itself.  I put the wall overlays down, glue in the curtains, and that's about it...well, except for the re-dos. With .005 glazing, .005 shades and .010 paper, only .020in per wall is taken away from the inside dimension.