Hi, I think I might have the 61-key Maccann concertina owned by Steve Gardham. It's got 60 keys + 1 function button. I'll open it up and see whether the number is 28,930.
I also have another one that seems quite rare - it's a Lachenal tenore, 36-button, F-key, made for a band (narrow range), silver tipped buttons, hallow shaft, SN 59,117.
Does anyone have any information about either of these?
Thanks!