I had to buy some special ball races to service and repair my TEAC TASCAM motors, these are not the cheap Chinese ones.

I Use now SKF, NSK or other major brands

These  bearings are probably used in the later
models as well, they are almost a standard size but very very slightly over too allow the shaft to fit in as the shafts were 7mm almost spot on but not less
in some case you could not get the standard bearing to fit the shaft.

In most cases you only need change the back bearing as it gets clogged up with brush residue moisture etc

Pack of two

STAINLESS STEEL!!!!!! inside and out