On Aug 20, 7:54*am, Pat Russell wrote:
Many gliders of that vintage were certified with forward statics
only. *Aft statics were a factory option, ordered by people interested
in accurate variometry.

Your ASI should be on the forward statics, since that was the way it
was calibrated and certified.

Maybe-
Best bet is to look in flight and maintenance manuals and see what
manufacturer said.
UH