I have a desire to make (undamaged) brick and cinder block walls. Is there some sort of sheeting material that can be placed over a solid backing such as plastic, basswood, etc. and then painted? Thanks.

Yes. You'll want to visit a hobby shop for this. Evergreen or plastruct (I forget which) makes a variety of brick-patterned sheet and stone-patterned sheet. You really need to see the sheets to pick the size you want. I personally find the stone patterns unconvincing, but that's just me.

I make my walls by making a shell of the brick sheet plus beams inside to give it depth, then more brick sheet 'skin' on the inner face. I then layer on smooth sheet in places where I want the interior plaster intact. Sounds harder than it is. I am preparing an article for AMPS Boresight on this who method...it is very easy and gives you the exact building configuration you want.

Tom, Danny's right Plastruct makes relief sheets of cinder blocks, dressed brick, rough brick, stone block, etc. They also have exterior wall sheets [ clapboard, etc. ] and roof sheets. The sheets are about 7" ? 8" x 11". They come in 1/24th, 1/48th and 1/35th scales.
Cheyenne