You don't really need a test board. When PS/1 stuff comes onto my bench, I just dump out my assortment of little PS/1 cables, etc. Of note, their test board doesn't actually allow testing diesel boards directly as they don't have the 4-pin tether they're expecting on that bottom connector. If I truly got a lot of PS/1 that I had to work with, I might consider formalizing the test set.
I just have this assortment of cables and components, I hook them up and away I go.