I've seen Schneider projection lenses for Kodak projectors. These days they go for peanuts if you can find them sitting around unused. They show up on occasion at camera stores. Yes, I know, camera stores are harder and harder to find.
No.1 Cardboard or plastic mount no glass is better with a curved field lens.
No.2 Slides in glass calls for a flat field lens.
The major difference of a Leitz projector over a Kodak or other branded projector is the lighting system.
EK and the others use a heat absorbing glass, to protect the slide. Leitz does not use a heat absorbing glass
but a Dichroix [SP] reflector to absorb the heat this results in a Whiter light on the screen.
This can be shown this way. Set up two projectors a Leitz and a Kodak side by side to project on a large White screen.
Use slide frames to open the mechanism and adjust the projectors to get the identical size os on the screen.
The Leitz will be a pure White while the EK will have a Greenish tinge.
I'm sure this will have some effect on a slide projection quality.
I am the original poster. I am more confused than I was. I guess if money didn't matter, would people recommend a specific model 35mm projector/ If reliability mattered, would it be another, and if sheer availability of parts mattered would people recommend another. I have gone on line and looked at ebay prices. For ektagraphic projectors ( there are tons of models) prices range from ridiculously low to 100-200$. For leitz or hasselblad we're talking a different price level completely. Judged only on the merits of the projected image, which one is "best", again, the price is not the issue. Thanks BTW I used to have a kodak carousel and stack loader and "GAVE IT AWAY!" a couple of years ago. It was OK, but I have 15K slides and want a high quality projector. Thanks Norm
Back in the 80's I wanted the best 35mm projector available. The Leitz projector was the best and had the sharpest glass and you could view a slide as long as you wanted and the projector wouldn't burn the slide up.
Unfortunately, I couldn't afford the Leitz so I bought a Kodak and put a Schneider lens on it. I had really close to the quality of the Leitz lens at a fraction of the cost. Of course I still had a cheap projector that would burn up the slides if I kept them in too long.
For optical properties alone, probably the Leitz should be your choice.
There were two tray systems used over time, earlier used the Euro style straight tray and later the Kodak Carousel type. Either of them work well but the Kodak holds more frames(80 or 140) than Euro(36?).
From what I have read the hasselblad pcp 80 works with 35mm, but then leitz has a number of pradovit models that also work with 35mm. Since I don't know anyone personally that ever used anything but a kodak carousel, I trying to learn from groups like this and the web. One of these days opportunity will knock. Norm