havent messed around the site in a long time.... but
HP PartSurfer provides fast, easy access to service parts information for a wide range of HP Products.
partsurfer.hp.com
used to carry almost any part you needed for DIY repair your paying full retail for the part but saving the $90 an hour service charge for labor.
if you can rebuild a winch you can rebuild a printer. especially in the newere HP commercial printer (LJ-4000 and newer) its all modular. i maintained the printer fleet for Wake forest for years. super simple stuff to work on.
and you can usually find an LJ42xx for LJ43xx used for pretty cheap. pop a new fuser and toner cartridge in it and be good to go for a long time.