Can you give me a model number?
Apple Tape 40SC - Apple part number M2640
Did some digging on google's usenet archive, and people were
trying to find replacements for the roller already in 1998.
The mechanism is a 3M MCD-40
There was one message I've found that says that 3M sold off
their tape drive division (or spun it off) as "GII" but I've
not found anything more on them.
Between bad tape formulations, and drives going bad, it is
becoming really difficult to inexpensively recover data from
10 to 20 years ago that was written to tape.