I built one for my II about a year ago, and I still have the jig and patterns I used. So since it's cold, and I had nothing going on I built two more. BTW, V8 only.
I don't know about price, it takes about two hours to make one, how does $35+ shipping sound? Anyone intersted PM me.
I'd have to see what other poly motor mounts look like first to get an idea of how it should go together. Maybe a two piece mount with a poly bushing between them... hmm... I'd have to round up some stuff, let me think a bit about it. I have rebuilt stock motor mounts, and in place of the rivit used a welded bolt. I was stretching the darn rivit, so that worked for a bit until I made the solid drivers side.