Some months ago I bought a model C2300 L4-B panel mount Airpath compass
from Aircraft Spruce and I'm not particularly happy with it.

It does not have an obvious leak. I don't recall seeing a large air
bubble when it first arrived but the bubble is certainly there now when
there is more than 3 to 4 degrees down pitch. In addition, the compass
card "hangs up" and will not rotate at more than a 25 degree bank angle.
This doesn't seem normal. Would appreciate any suggestions for a fix or
perhaps a better quality compass.

Angier Ames