I bought my first BMW in 1967 and almost immediately replaced the (awful) bench seat with a tractor-type saddle. Almost everyone I rode with did the same. As I recall, mine was a Bates model, later replaced with one from a Harley (which I still have but recently replaced with a Corbin). I bought a full-face Bell Star helmet at about the same time. Davida helmets were nowhere to be seen. Most riders I knew either offered their heads to the crash gods or wore fiberglass buckets that were precursors to the ones most of us wear now.
Jon Miller
'67 R69S
'13 F800GT
Altadena, California