Well I've decided to simply change the front driveshaft, then there'll be one less thing to worry about. Got a new one on order from BP Utah.

It was budgeted for anyway, and it's looking like this vehicle is in excellent shape otherwise. No exhaust gases in the coolant, no coolant consumption, passes smog, everything seems to work (even the central locking and both sunroofs!). So far the Ebay gamble is paying off.