if you know what you are doing then it is possible to change the bearings, you will need a new seal too, if the shaft has not contacted the inside walls of the pump then it's worth repairing it, i paid £120 for a recon pump with a 12 month warranty, 13 months later it died, my neighbour had a look at it for me and gave me the old bearing and seal to replace, i got the new parts for £6 and it lasted another 4 years after that, may still be going but sold the engine s i don't know
and no a mk3 pump pulley wheels sits out a touch further than the mk2 so the belt will be at an angle