Indeed I do, you cannot do this sort of work properly without them.

In fact, I have some of the coolest cassette deck-specific tools available, custom-made for working with cassette decks and these are necessary tools of the trade.

My stash includes various calibration tapes including a custom Pioneer set for use with the CT-A9X and others, special mechanical tools, electronic test and measurement equipment, a TDK electronic tape head demagnetiser, and TEAC hand-held demagnetiser and a hand-made (by me) mirrored tape path cassette. I also have a range of hard copy original manufacturer service data and manuals.