Yes, not an easy one but must be out there somewhere.
Speedo Int. Customer Services have been helpful before
with archive material.
There are also collections at Powerhouse Sydney and a
big stock at allposters.uk
In the meantime the Michael Phelps of the Gay Games
(Cologne 2010) posted some pics of proper speedos here:
http://jackmax2.wordpress.com/2010/05/03/countdown-to-
the-gay-games-cologne-part-1/