Crying over Harborside Mansion

So, Harborside Mansion came together beautifully! After some frustration with the warped baseboard and crown moldings from England, and a few hiccups with the arch (new arch did not fit the opening we made and the hole had to be enlarged), and momentary heart failure when the stairs didn't fit correctly (spent an hour or so sanding and chiseling away at stair hole opening), the day is finally here when the customer is coming to pick up the house!

Colors and papers the customer picked out are lovely, archway is amazing, floors are stunning (especially with the stairs!) and all that is left to do is to cut crown molding for the dining room and bathroom! I go in to work an hour early to cut those pieces and glue them in so it's all ready for the customer who will arrive just before lunch. She will finalize some baseboard decisions in the library and kitchen, leave to have lunch, and while she is at lunch I will cut the baseboards and install them. I love having a plan!

Living room looking great with lights on and stairs in place!

Arch really adds a nice architectural detail to this conservatory!

Until that plan blows up in my face.

Arrive at work early and realize the dining room and bathroom are in the bay part of the house. Baseboard was cut at a 22.5 degree angle for these rooms and did not fit exactly perfect, but with a tiny bit of spackle and paint it blends beautifully. But the crown is thicker and 22.5 degrees isn't working at all! I cut a dozen pieces without one fitting quite right. I'm pulling my hair out in frustration. Dad arrives and offers his sage advice: it's not a 22.5 degree angle; it's a 30 degree angle. My hero: Problem solved! He starts to cut me pieces as the customer arrives.

While showing the customer her house we turn on all the lights. The house lights up beautifully (as it had in the weeks prior as I was working on it, including that morning when I turned it on to show another customer how pretty the sconces are in the attic). Then after a brief moment, the lights all flicker and act strange before going out. Transformer overloaded? I count the bulbs; no, we are at 49 bulbs and 12 outlets for future lamps and the transformer is rated for 64 bulbs so we should be fine. Long story short: lights on first and second level eventually come back on, but third floor is still dark.

Attic Bedroom all finished except now light is not working.

All the pretty sconces will be very dramatic with the mirrors the customer has for between them.

I don't know if any of you recall, but this house was wired originally by someone else. We moved the outlet level runs up (had been 1/2" off floor and impeded the baseboard installation so we moved outlet runs up to 1" off the floor) and we removed the tapewire from the ceilings and put tapewire on the floors above for ceiling chandeliers. Where the power comes into the house someone wire with these absolutely wonderful switches that operates on each level:

Wires going from the back of the switches (located on the exterior foundation) to the runs of each level.

But I'm not sure what the red wires are leading from the switches to the tapewire. Are they rated for the proper amps needed for a dollhouse to operate? Yet, it all worked in the weeks leading up to the customer coming to get the house. I am hoping that if I replace or repair the red wire for the 3rd floor (notice it is spliced in the middle there for some reason - wonder what that is all about because it was like that - I haven't repaired anything yet) it will all work again. Right now when I test the tapewire labeled 3rd floor, the tester glows very faintly before clicking off (like a short maybe?) so I know there is power there, but it's weak and turns off quickly for some reason.

Wiring under the house: I'm hoping the problem is here because I don't want to rip up wallpapers and floors!

I am trying hard not to cry (as I'm sure the customer is too as it is heartbreaking to not get her dollhouse like she thought she was -- but I can't send her home with a house that doesn't light on the 3rd floor!). And I am scared to death that the wiring issue will involve ripping up wallpapers or floors to find the source of the trouble: something I do not want to do seeing as how pretty everything is right now (plus all the time it would take). If anyone has any ideas I am open for suggestions, because I am stumped and only have 2 more days to find the problem before the customer returns to get her house!