[Ron Walker]

This is curious. The old McDonnell planetarium (St. Louis) had something very close to the Saturn or L1, but not exactly the same. The SLouis projector had cowlings aroudn the planet cages (you couldn't see through each planet segment. Meanwhile, the vanderbilt planetarium had a "new generation" large Goto (which had big advertising letters - logo - on it and a novel set of analog computers in the base. I think those computers would allow the operator to reset the observing time without having to make the mechanics whip around repeatedly.

I believe the Spitz Jr. is the only older planetarium that was duplicated exactly from machine to machine. Every projector that I have seen has had a certain amount of custom work done to it. The SLouis planet cage cowlings were probably used to keep the projected images off the floor very much like the original Zeiss one planet cage.