I can actually remember those little hand-held gadgets for stereo shots that were common in the sixties. I didn't like them much, they seemed a nuisance, but even though the transparency image was likely to be quite crisp (you're looking at it very closely) it wasn't as entertaining as a single slide projection onto a white wall. I suspect it's largely because of that closeness (lack of magnification) that stereo cameras could often get away with pretty poor lenses - like on the Wray/Graflex sample you saw.
Someone mentioned a Kodak and from what I read it had better quality lenses, but ... if you're thinking of looking at them onscreen or printing them rather than in a viewer I'd look into taking two shots with an SLR (lean on your left foot, then second shot, lean on your right foot) or even mounting two cameras side-by-side. This entails more post-proc work to ensure vertical registration, etc, but the quality would be way, way higher (as I found with my pair from a dslr) though maybe that just depends on how you plan to view them, small or large.
I have a project coming up where I'll likely use the Wray once more as where moving people are concerned you definitely want simultaneous shots. However, I'll be looking to use a grain-free film this time. (Ooh, the price of slide film these days!)
There's something exciting about the prospect of good 3D work but I sort of wish there was another way to view them onscreen without resorting to anaglyph glasses. You'll have no want for reading resources if you check what physicist/guitarist Brian May has been up to ...
http://www.londonstereo.com/
