Can a Delineascope GK projector safely show 6x7 cm slides?

[sbjornda]

I'm looking for a bargain slide projector for 6x7 cm slides in plastic mounts. There are plenty of 6x6 projectors, but the 6x7's seem to be pricey - this is a hobby for me, not a professional gig. I've seen several Delineascope GK's advertised but I don't know how they work - is there a carrier or mask that would prevent light bleeding around the slide mount? And does it operate coolly enough that plastic slide mounts won't warp? It looks like it uses a 750w bulb, so plenty of heat. And is the focal length of the projecting lens too long to be of use in a typical suburban home?

I'd appreciate any information anyone might have.

Thanks,
Sterling