ID the manufacturer of inductor

[Alex Eisenhut]

I opened up a 1982 disk drive (a Commodore 1540) and noticed inductors in an unusual case style. Blue blocks with no markings and none of the several service manuals I have mention a manufacturer. They do for the 1541 and 1541-II but AFAIK none of those have this style of inductor.
Those inductors in all other such drives I've seen over the decades all come in the usual blue blob with color dots, as seen also in other electronics of the era, like TVs.
They're not broken or anything, I'm just a huge nerd and I need to know such things.