Thanks for all the feedback. This is helpful for me to think through causes, solutions, and whether a solution is needed.

The bike doesn't feel great no-hands, but I'm not leaning it to one side to maintain a straight line as I am with another bike I picked up used.

The seller included the original wheelset, and I will check the spacing on the front wheel to see if it was 100mm (which would give me an idea of whether the fork spacing was manually spread).

Most mechanics nowadays don't have experience cold-setting a steel fork. 20 years ago I'd have had more luck on that issue.

I'll likely do a slight bit of filing on the underside of the longer fork dropout. It's even possible that paint chipped off on one side and not the other, which could account for the slight difference.