57 waterpump dilema

[Quentin Hall Australia]

I have a spare 57 waterpump that I have been kicking my toes on in my shed so I decided to rebuild it. I have done a few of these over the years with satisfactory results. However I have Never liked the seal running raw aganst the cast face backing. 5 years of limited use and they need redoing.
  This water pump had been lying around for years and was heavily scaled with rust so I dropped it in my phosphoric acid tank overnight to descale it.
  Only drama is that the tank must have evaporated alot of water due to the hot weather and hence it was a little more aggressive than usual ie it got rid of the scale beautifully but now I have a sloppy fit for the bearing. I just tried a "Coke can shim" and that will work??? I still have to get the seal face machined. I found a new style bearing that has a ceramic insert but I would have to machine the bearing face considerably and there isn't alot of meat there and the drip outlet also presents another hinderence. But I am confidant it will just sneak in. ?
   I have heard of some reversing the seal and facing it off the impeller. But how to secure the spring loaded seal to the water pump body?
A. Will Coke can shim suffice for bearing?
B. Any one recessed in a ceramic disk in leiu of refacing cast iron?
C. Any one reversed the seal and run off the impeller?

[selmawp]

Hi, if it is not to late I have a solution to your problem, please let me know. Thanks Tony.