TU58 tape formatter (was Re: rebuilding DC100A cartridges?)

Hello. I have a VAX730 with both TU58 drives destroyed (capstan melted, need replacements). I also have a bunch of cassettes, but unfortunately all seem to have problems with the bend and/or bad spots on the tape. Possibly I would try to replace the broken bands (if I find a source) and/or replace the magnetic tape when damaged (I was thinking to try with audio cassette tape, don' t know if metal oxide high density tape could be good for it). Anybody has some information about the coercivity of original DEC TU58 tape? One problem indeed is the need of reformatting the tape, but: if I can emulate the TU58 drive using a serial, would it be possible to send raw commands to the drive using the serial and a PC? Andrea PS-If possible, some good-condition cassette would be very useful to me too. I'm located in Italy.