I have the same carb and a delrin needle and took the carb apart
recently to check for trash because a friend told me he found a
dirt-dauber in his float chamber. I was running a little lean. I
replaced the big gasket after finding nothing inside.

This carb has always worked well and not dripped even though the fuel
run through it may vary.

I have rebuilt several of these very simple carburetors and think a lot
of them, but they won't give you the oomph or diversity of a Marvel
Schebler.

The mix control is working on mine but it doesn't kick in until you get
to something like 1500 rpm, making it almost impossible to kill the
engine by starving the mixture, although it CAN be done by completely
leaning and firewalling the throttle.

The last Stromberg NAS3A1 I rebuilt we tested on the bench and the
steel needle would not seat completely. It dripped a little, so the
A&P/IA who signed it off whacked the needle against the seat with a
hammer. Which stopped the leak. Don't ask me how hard to hit it.
It must be done gingerly, deftly, prayerfully.

BTW, the ultimate authority on Strombergs is Neal Wright (Cougar) of
Sacramento.