I thought about making one for my Galaxie by using a new gallong paint can/lid from hardware store. All you'd have to do is have inlet and outlet and on the outlet side you could plumb in a cheap one way valve toward the engine. I was going to mount both inlet/outlet on the lid and JB Weld the lip and tap it into place. But, Summit had them fairly cheap so I just went that route. You could have as big a reservoir as you wanted to build and have space for, all you gotta have is inlet and outlet, the actual one way valve doesn't even have to necessarily be mounted in the vacuum can. I think Ford must've bought surplus coffee cans, because that is exactly what the stock one in my galaxie looked like, a coffee can.
