Thanks for the compliment on my Panoram pics.
D'oh! I forgot to mention the 2-6-10-14 spacing. Sort of an important thing....
I've never tried multiple exposures, figuring my (sorta light) tripod would move. I've also read a claim on the Net that a guy manually moved the lens back and forth (spring pressure is really light once the lens leaves its nest), but that would seem to have issues as well, and I cannot confirm or deny.
In low light (unless it's *really, really* low), you could take 400 speed film and the low-speed lens setting (high is about 1/100 and low about 1/50, near as I can guesstimate) and then push-process it. Since there's only 4 frames, it's not like it's going to just sit in there.
And if the light was really low, that may be why you had no light leaks. I hope you don't have light leaks, but be aware you may still have them on a bright day.
I also tape over the ruby window with gaffers tape, and then just peel it back when advancing film.