I had been working on the assumption that you could only search for the broadcast code, such as BYYC. I didn't realize you could search by the prom number.
Glad I could help. Just out of curiousity, does the list from Dave include prom part numbers?

It's not too hard to add a ZIF socket to the memcal and switch to a flash chip. A couple of 27SF512's work well to take the load off the eprom. And you can attach an emulator fairly easily as well.