So since my last post - I swapped out the 6200's logic board with one that I saved from a 5260/120. Huge improvement and I also added a bunch of other spare stuff - ethernet, TV tuner, AV card, etc. The 6200 came with a 256k L2 cache card that prevents the 5260 board from booting but works fine in its original home... don't know what's up with that.
Haven't touched the LCII's - they're on my winter repair list.
I did dig through my box of expansion cards and found a "2-8MB memory expansion card", an ethernet card, and a 50 pin SCSI card for the IBM. I think I saved them from a dead PS/2 I tossed years ago - never thought I'd find a good home for MCA cards!
I also scored again last night and bought two G4's - a 400MHz Sawtooth and a 733MHz Digital Audio. Both work great but the DA is kinda beat up and missing two bottom handles/feet. I also got a Cinema display of some sort that is missing its power supply unfortunately.
The biggest score was in the DA - It had a Sonnet Tempo-X SATA card! :O AND, a 4 bay external SATA hard drive enclosure full of 250GB drives! I haven't figured out exactly how to make it all work yet and I think one of the drives is dead but it was totally worth $30 for the lot!