Congrats on the Sherpa; she's a beaut.
Just before moving a year and a half ago, I had to sell
my Alpina 250...pained me to do so but allowed me to
keep my R60/2.
My feeling is to not worry too terribly much about the
original equip and ride the damned thing! I got lots
of pleasure from my '74 and they should be ridden.
Best of luck!