JohnC wrote:

Many years ago I purchased a frame mounted clip that attaches
to the bottom tube. It is about two inches long and when open,
it locks against the front tire essentially keeping the bike
from rolling and acting as a crude stand when the bike is
resting against something.

That was a "Flickstand", made by Rhode Gear. I had one of them on my old
Fuji "Grand Tourer" and it worked well for the purpose.

Does anybody know where to purchase one of these?

They disappeared after Bell bought Rhode Gear in 1989.

--
"Bicycling is a healthy and manly pursuit with much
to recommend it, and, unlike other foolish crazes,
it has not died out." -- The Daily Telegraph (1877)