> Usually they were just slapped on, clamped to the seat
> stays and would
> tend to slide down stripping paint as they went.
> I later found out that in the supplied hardware there was a
> T bracket
> that reached the brake bolt and arrested this behavior,
> I'm not sure if this was always a standard piece that was
> just ignored in most installations...
Marcus,
If my recollection of ancient history is working well, the T brackets didn't appear until 1975. Before that, you made your own, or bought an aftermarket piece. Also, at one point, Pletscher sold the racks with an "improved" style clamp that they eentually abandoned. This style used a strap that wrapped around each stay. I _think_ this style was abandoned when the T-bracket became a standard part of their mounting kit.
Cheers,
Fred Rednor -Arlington, Virginia (USA)