Found this website while looking for LED stuff.
https://evandesigns.com/collections/hobby-leds
They also have a really neat software kit for printing buildings on decal paper. Software allows you to pick from standard things, scale as needed, and add details (doors, windows, etc), and print on matte photo paper. Then attach to substrate as needed (wood, cardboard, posterboard, cereal boxes, etc). The gallery below shows what is possible. They have a design-sharing site also.
https://evandesigns.com/pages/custom...ings-gallery-1
As with most things, adding some 3D details (like an open door, G-scale shrubbery, interior lighting, etc) makes all the difference.
If someone wanted to make a large batch of knock-down buildings for assembling at a show, I think this would be a huge help. Making wall panels from 1/8 or 1/4 hardboard, using mating corner brackets so the walls can be connected by simply dropping screws into teh brackets (1 screw at top and bottom of each wall intersection), covered with glued-on photos - this could make it happen! A roof structure only requires a few tabs that sit against the inside top of the walls, to keep it from falling in.
This is geared toward model railroading, so perhaps there are other options out there.