Hello Dave (not Dace, sorry)!
Thanks a million for all your help through your manual. It is a newly made Eiru concertina from Sean Garvey's Irish Concertina Company in Dublin, Ireland; being from up the road I wanted to shop local, as it were, even though I don't live in Dublin now. So to answer, it was custom made for me with my own key specifications (like a drone D, and C sharp options etc.). Does this newness-of-the-instrument change very much how I should be approaching any issues? As in, should I be treating this newly made concertina in any particular way? This really is a minefield for me, but I am fairly confident that my explorations are not going to do any harm to the instrument, touch wood.
Again, thank you to everyone for helping.
Ruairi