Given that whatever you buy as an alternate box is likely to seem inferior to your Jeffries and will still cost an appreciable amount of cash, why don't you save yourself a lot of money and just insure it? That way you get to take the Jeffries out to play and you don't have to worry about how much its worth.
I have a great old Jeffries but I am more than a bit nervous about traveling with a concertina
worth more than anything else I own, aside from my house.
I'm reading these posts and enjoying this discussion a lot. I'll tell you all what I learned and ended up with after people have stopped commenting. I've been playing concertina going on twenty years now.
(A bit off topic, but...) By the way, I went to a wonderful session last night that restored my faith in sessions- it was at a small pub in Cree, Co. Clare. Aside from a whistle, a flute, two banjos and a guitar, there were seven concertinas in attendance, never playing all at once, thank God (forgive spelling errors): Shea Fogarty, Frank McNamara, Tom Driscoll, Colin Sheehan and his Japanese friend, Mark Davies, and Tom Carey. Not me. Out-classed, I played my flute all night. I was surrounded by great musicians.
It's a movable feast and we're going to do it again tonight. It was a relief to play after a spell of disappointing sessions in this changing Ireland. Jigs and reels exclusively, non-stop from ten to two in the morning, not a single hornpipe, and some great singing from West Clare locals.
Re: insurance- that might be expensive for an instrument valued at well over $10,000. And even if I were recompensed for the loss, I doubt it would be very easy to find a comparable instrument off the shelf. I always and only travel with carry-on luggage, which includes a lap-top and a flute. I'd like to minimize the stress level a bit by not having to worry about a practically irreplaceable instrument. And who wants to deal with a recalcitrant insurance company after a big loss? Not me.