Just an Idea, why don't you try to make one from 2 pci connectors?
It's not elegant for soldering, but good enough for prototyping.
I made one myself, and long time ago one from 2 isa conn. for A500.
I have bought an Apollo1260 from WonkeyDonkey originally from FitzSteve. And this card has contact problem from the beginning. My electrican has new rev6 CPU fitted new Oscillator fitted and the same problem. He measured the mistake out and says the problem is the expansion slot connector. That must be chanced and the card will be stable. I tried to buy it from kipper2k but he did not answer. I want to buy this for this. But thanks for the Idea! Greetings!