There is a 2" 36 on gunbroker stamped 36-1.
Was there a 36-1 before the 3" heavy barrel?
perhaps a limited run of something?

Never say never with S&W but I have never heard of a 2" Model 36-1. I would love to see the end label of the box of the referenced example.

Although I don't see any evidence, it's possible the barrel has been replaced by a previous owner who found the 3" heavy barrel didn't meet his/her needs.

It's also possible that a 2" gun was assembled at the factory and the fitter happened to pick up a frame marked -1.

Russ

I think I would want a Letter from S&W on this one prior to laying out some serious money.