I've been wading around in slides, trays and stackloaders for several years. The short answer for compatibility? Possibly. That's probably not what you wanted to hear, but I say that because like any industry, manufacturers often copy what is a leading product and release it for sale under the auspices that it will work just fine on your projector.

The fact is, it might, and it might not. I had several trays meant to work on Kodak carousel projectors, and although they worked, they also hung up when trying to get them off the projector. They were also cheaply constructed, and I eventually got rid of them. If you are looking for advice, I would suggest this: Find a tray/projector combination that you are happy with and that which was popular enough in America at one time so you can easily get OEM parts off auction websites. Avoid the unique and rare set-ups, or you will be pining for some damned part that is unavailable. Match them up in one manufacturing line so your parts are interchangeable and they are wholly compatible.

I use Kodak Ektagraphic III line of 35mm projectors with 80 slot trays and Hasselblad PCP 80 projectors for 120 slides mounted in Gepe anti-newton mounts.