I have no concertina experience (zip, nadda, none)....a year and a half ago I came across a Lachenal Maccann duet in reasonable shape and sent it off to the button box for a thorough overhaul (but not retune to 440) ..... I've never been able to master the fingering....
Recently, I came across 2 disfunctional old Bastari 20 buttons and decided I could swap parts make one that works (sticky buttons and all)......10 minutes after assembley...picking out simple tunes..no problem (the rumors must be true)
I put the Mccann on EBay but no bites...etc...it is still in high (Phiharmonic ?) pitch....
Should I have the Mccann retuned?......expensive and then try to sell it?
Try to trade it for a 30-button anglo as is?
Try to retune it..I think I could but it would be a slow process...ssssllloooooowww
Juggle and replace reeds to make the Mccann an anglo.....heresy!
Take up the keyboard accordian......?