Somehow, during our ride yesterday, the master cylinder cap came off of Leo's Convert, bounced off of his leg and into the weeds along Mountain House Rd. near Hustontown, PA, never to be found. A wasted 1/2 hour of searching. Seems to be a trend with him - he once lost a Bing carb float bowl off of his BMW R75/5 near Berkeley Springs, WV (I found that one after an hour of searching).
The master cylinder is the type with the plastic reservoir, common to many Tonti Guzzis of the era. The original cap was metal, but metal or plastic will be fine. Anyone? Thanks.