Info on brake calipers

[pmeis@bgsm.edu (paul meis)]

My 1969 D-sports racer runs H&H 500 brake calipers. I am seeking any
information on these odd little pieces, and, hopefully, would like to find
some spares. Standard calipers do not fit my uprights, which are cast to
fit these tiny calipers. I am told the original application may have been
3/4 midget. The pucks are similar to Kelsey-Hayes 500, and those calipers
may be similar. I would appreciate any information and leads.
Paul Meis, Team Escargot