I am looking for a front right foot peg and I was wondering if they are all the same for the various K models. 
For example looking at one from a late 80s  K100 RS. Would that work for my 91 K75S?

Any other model of BMW that might have pegs that fit on these bikes???

Thanks in advance.

The early, '83, '84 & some '85 footrest pegs had bolt on weights on the ends but anything later should fit your '91 K.

Paul.