[sugarmaker]

51505bat,
That is the plan! Great minds think alike! I have the jig borrowed from my friend Bob, ex Model A guy, now 55 Ford Crown Vic guy.
I plan to router in a 3/16 pocket into the top inside edge for a piece of Luan plywood to be mounted. Glued and brad nailed. This should support the springs and insulate them from the top of the tank.
Also router a lip into/ around the underside of the frames for the fabric to be attached.
Then fit and fasten the springs to the wood base.
Do I need them now with the engine out? Not really. Just keeps the project moving.
regards,
chris