After the original failure, I loaded a roll of FP4 and took the Vigilant to Deerfield Fair. The results were equally poor.
This was the only remotely salvageable image on the roll.
I don't really know what is going wrong. My best guess is that the bellows may not be light tight. The spaces between the images are not fogged, so it does not seem to be a general light leak in the body.
It looks good on the shelf, though.