I've never done more than repaired a concertina a bit, but if the reeds are as dear as Bob Bolton says, then some entrepreneur should look to getting a million or two frames made in India. They seem to do a LOT of brasswork and non-ferrous work, at very reasonable prices, and a toolmaker could final-machine the frames in their various sizes and fit the tongues, which could possibly be obtained from a springmaker and ground to size, and then all that's left to do would be tune them, and...
Ah, I see why they're so dear. Just for a moment there....

It must be good fun trying to source those long skinny screws that hold the thing together, too. Everything on musical instruments seems to be absolutly specialised. Except on Pacific-Island-built ukeleles.