Alan may be on vacation so I will start this post a little belatedly.
I just finished up up on my first N scale building. It is the Walthers Grand Union Station kit. It was surprisingly easier to build than I first thought.
Fir the building paint color I first sprayed with flat black (about 90% coverage) then followed up with dark gray. The mortar is Robert's Brick Mortar.
I added two interior walls to block the building wings from the main section plus some flooring to hide the expansion joints I made in the Masonite 'concrete' base.
If you look carefully at the last photo you can see two Woodland Scenics plug & play wall lights. Talk about thin wires....................