Ross just re-reading and see you say rear "bearing slides" I cannot see how pre-load can be done without this bearing sliding, I cannot get this off even with puller as only place to get puller is outer race so don't want to put to much force on it. I'm thinking using a press but this would be forcing against plastic pulley with the force being applied on the damaged (threaded) end of spindle can you see any problems as I don't want to damage pulley.
just read thro your repair post. What happened to the chap (bogstandard) you was communicating with?