Sadly no suggestion, but I too would be very interested in other's feedback on this topic. I recently manage to save one of my IIgs' 800K drives, but broke the other one in a similar manner than you. While trying to fix it, I disassembled and messed around with five of those drives, from the IIgs, a Mac Plus and a SE. Now I have two of them working fine, one completely blocked with a badly bent part in the eject mechanism, and two with a loose upper head, just as yours.

I'll folow this thread with greates interest, since I haven't got rid of those broken drives yet!