I am just completing the building of an N scale freight depot (Pola N209). I painted the windows white and they look pristine, like they've just come out of the factory. What is the best way to tone them down so that they look their age?

I should add that the windows are installed (but could be removed). They are not (yet?) glazed.

I've been considering, for some time now, an engine facility on a T trak module (most likely a double, possibly a triple). Obviously T-Trak  modules aren't big enough for a turntable with more than  a few tracks, but a transfer table with 8-10 would fit quite nicely. I don't want a just a display piece though - I want it to operate.

Square corners satisfy.  The MicroMark gluing jig is a good base, and the Coffman right angle clamp works well with 1/8" masonite in two of the pictures below. ( both MRH sponsors )  

I came to model railroading about 10 years ago, and I split my hobby time between model railroading, 2 other hobbies, and continuous renovations of our 170 year old house.  I also live in an area where the nearest other modellers are a couple of hours away.  So, I am not very long in the learning curve.  But I do still have a steady hand and good patience.