Both my Savoy "F" and Miller "Bfl" developed sticking buttons that would
not return .. they'd stick down.

Both were caused by the button touching the wood around the button hole.

I "fixed" both by using a small "jeweler's file" and ever so carefully
trimming the rim of the hole towards the inside of the finger board.

I'll bet it's the cold, dry weather and contracting wood?

Too much of a coincidence!

--Big Nick

Another reason to never leave LA!

Ah Ignorance is bliss. I just bought my first button acordion (it was very cheap and from the 1800s). Most the the flappers were sticking and not seating correctly. I couldnt see a way of getting the fulcrum out so i just squirted some 3in1 oil down there and wiggled them about a bit. Seems to work, but my main concern is that the oil might go sticky with time and make things worse. I also took a pair of pliers to the connecting rods and bent them back into shape so that the flappers sealed. All seems fine so far.. but maybe i'll be a bit more careful next time.