Here are some other resources on the web related to Commodore PET, Commodore 64, Tape Drives and Disk Drives. Perhaps there's a something useful for your specific situation.
Larry's Commodore PET/CBM FAQ - CROSS-PLATFORM AND EMULATION
http://www.6502.org/users/andre/petindex/transfer.html
http://www.commodorepet.org/downloads.html
http://www.zimmers.net/anonftp/pub/cbm/crossplatform/transfer/datassette/index.html
I'll add more if I find it or if someone asks!
Email me at chiron (at) chiron bramberger (dot) com