Kestrel 19, two static ports in the tail boom, pitot and TE in the
fin. *The TE line is split under the seat using a Y connector and then
travels to two varios (a Winter mechanical and a 1990-era audio/final-
glide called a VariCalc). *Pitot and static lines are split behind the
panel using T connectors.
I replaced all the non-permanent tubing last year and they all seemed
to be leak-free.

Tailboom static. Prolly used to work OK till you fixed the leaks.
Simple test. Unplug the static tee from the tailboom source and let it
use cockpit air. Fly the ship and try to recreate the creeping
readings while using cockpit static. Lots of older ships had their
tailboom statics relocated due to errors induced at that location. At
least it's an easy test...

-Paul