G'day Schantieman,

That certainly sounds like a bandsman's instrument that you have there! If I had it, I would retune it to G/D ... not by filing away at the reeds, but by carefully moving each reed to one position higher in the instrument's scales.

Most of the reeds would fit into the adjacent slots, as there was only a half dozen, or so, reed shoe sizes used by any manufacturer. As the few that didn't fit would be tight (going into a smaller slot) a few slots would need opening out with a specially angled scraper (concertina repairer job ... unless you know your way round concertina innards ...?).

There would also be a few accidentals from the Ab/Eb keys that needed retuning (or, in my case, swapping ... or, at worst, re-reeding ... with/by my friendly concertina maker/repairer: Richards Evans, in the Blue Mts, New South Wales, Australia!) - especially if you have only a 2-row instrument. If it is a 3-row (30-plus keys) there should be a fairly complete set for the new arrangement ... maybe a need to find the lowest note on the G scale.

I do admit that I usually have a few loose reeds available in deceased or ailing instruments ... but my point is that it is probably not necessary to actually retune many reeds - even by a semitone - in moving to a much more amenable key set.

Regards,

Bob Bolton