It wouldn't take long for me to crank out some 16x16 and 32x32 blocks to use. That being said, provided it was backwards compatible with Backbone (for the time being) and open sourced, I'd be down to setup some graphics. Maya still supports Amiga IFFs as well, so I could make some top down dungeon blocks, if wanted.
Off Topic,
Samurai, all the under the hood stuff for BTBuilder is done, so now it's 100% compatible with both the PC and Amiga BTCS binaries. In fact, we've added up to 960x600 support, 9 (I think I did 9?) tilesets, animated picture slots, sound, blah blah. Dulsi took a break to do some reading and I'm currently focusing on some low poly animation work so I think we're done til the new year, but pretty much we're at the point where the Editor needs to be done, so you might want to have a look. Oh, it's got a crude, but effective map editor now, but it doesn't allow you to lay down specials or modify them. Maps, Monsters and Spells, though are xml compatible and can be hand edited, if need be.