Yeah if that is the situation, I can’t see that sourcing replacement heads is going to be economically viable. If so, the idea to sell them for parts is probably the best one.

Did you purchase the 808 (the matching CD player)? If so, that should be good to go, with or without Meridian speakers (it’s a world-class CD player/DAC in its own right).

Alternatively, you could try returning the speakers to the seller, since you haven’t been sold the whole speaker, just the bass units, and they are useless as-is.