This is the most relevant bit:
I've completed the most difficult portion of the hack! / install a 6360/6500 MoBo / in an actual Classic . . .
This pic shows how I've joined the inverted 6500 MoBo slide/mounting plate to what little remains of the Classic Chassis.
This shot shows just how close a margin there is for doing the Compact Mac Shortbed Takky Hack!
and here's a closeup, notice the contorted bending necessary to retain the original equipment Medusa Cable Harness mounting slots...
If I were to do this hack without the Cellar Expansion Bay, I'd make sure to shore up those heavily rework hardened slot arms so the 6360/6500/1 slot riser MoBo could be slid in-n-out with impunity.