I received the 2 roll hoops from rollcagecomponents today. They look great for $85. I'm sure the $2800 ones would have been greater.
I milled a quick and dirty mold from a 2x4 and some bondo fill to make the motor mount rubber and have been pouring those over the past few days. They seem about right. One side is flat and it's other side has a cylinder boss sticking up about half the thickness of the motor mount plate. I'll need to make some washer-like spacers so I can adjust the height. There will be a crush tube that need to be cut to a length that will pre-load the rubber a little bit.
I use the same urethane I used for the suspension bushings. A 70 shore, I think. I "Johnson paste wax" the molds before each casting, but the urethane rubber is still hard to get out, needs more draft, or the molds should be made of silicone. Pro tip: Demold at about 15-20 hours, not 50, it seems to stick more with the longer cure.
I turned some inserts for the pushrod/tie rods and welded those in. I "plug welded" (can't think of the right term for that at the moment) 2 spots around each insert, and of course around the seam. I'm sure I ordered jam nuts, but I can't find them.