Strange thread. My most comfortable saddle is a 50 year old unpadded plastic saddle - more comfortable by far than any modern saddle I've tried, so I'm going to call nonsense on this one. If a saddle was doing you "harm" you would experience symptoms like numbness and discomfort. Also a saddle that works for me might be torture for someone else, modern or vintage.

Also, for the record I do have a slavish devotion to vintage.