Finger and Toe Models (yes, that's really their name) makes a set of paper buildings in 15mm called Shanty Town, and an expansion with shops, that I picked up in PDF form from RPGNow.com. Friday I decided to print one set out on cardstock, and Saturday I cut out a single shack and folded it to see how much difficulty there was to it. Folding all the slender tabs down turned out to be more of a nuisance than cutting it out, but I managed it. I haven't yet dug up where I put my glue to try gluing it into a finished product, but as long as that part works well, I think I'm going to be reasonably pleased with them.
I also pulled out a Maisto M939, of which I have several I got cheap off Ebay a few years back, and stuck the gun shield and gun from a Roco 105mm howitzer in the cargo bed. At the moment, it's simply wedged in, not glued. The 939 is technically too late a model truck for my needs, but it'll do in a pinch. I'm waiting until the first of the actual 1/100 models arrive to see how they compare in size and decide whether I'll use the diecast with them or not.
I also put in an order for one set each of 15mm Grass Huts and Blast Markers from PaperTerrain.com, who are currently having a sale. I'm curious to see if they'll work well for me.