I've never owned a Commodore PET (I own a VIC-20, C64 and various Amigas) but I was going through my collection and found some manuals for one.
Not sure what they're worth but I put them on eBay:
http://www.ebay.com.au/itm/121033397500
http://www.ebay.com/itm/121033397500
The assembler...