(tuning and repair)
Each bandoneonist should have basic knowledge about how his instrument
works. Few were dedicated to make their own maintenance. However,
most of them made severe damage to the first instruments they tried.
If you want to save your bandoneon and money, give it to a prefessional
if it needs to be serviced.
The addresses below list places where you can find service.
I can't give any further recommendation since I haven't used their
service.