If your accordion needs fixing...

[Anyanka]

... e.g minor repairs, farty valves, rattles and shakes inside the box, out-of-tune reeds (but not full re-tunes on ancient boxes), altering the bass configuration on 48-bass boxes to be more folk-friendly - all with short waiting times and very reasonable prices - then this guy might be your man:
http://www.martindudley.co.uk/accordions.html

And just to make my own involvement clear - he is MY man, and I do let him open up my Pigini