I do recall a sale of the cartridges in the 80's sometime here in
Southern California, when everyone turned up with cartridges (and few
drives). The floppies could be pulled and used quite nicely with AT
drives, so a lot went that way.
I may have a banker box full of such media somewhere, if I run across
it, I'll post here in the future. Probably hidden like Fred's pile of
treasures.
I think the media was represented as similar to the Drivtec as far as
repurposing it for AT use.
I don't know that any of the media like that was that great as far as
how well it lasted, but I did use some Drivetec media in such a way.
I think when the Amlyn cartridges showed up, I kept the cartridges
because the AT media was then showing up cheaply at the local swap
meets, so the temptation or need to use it for AT media was not there.