I am not a pool or pump expert, but I have rebuilt a few tractor engines while restoring an antique tractor at my ranch. I learned over a 4 yr period on weekends of restoring this tractor, if a part was too worn or decrepit, I replaced it and did not toss good money at bad conjecture. I also learned that before I did something, I checked w either a technical service manual or someone else that did it before via 2-3 diff tractor forums.
While working on your own nickel for time and your own dime for parts, it is your right to do as you wish. However, there is a time when you need to examine your time, money and labor and make a call toward efficiencies and reliabilities. My suggestion is to save the bondo resin repair [which I did use to repair a 1951 J-Deere MT tractor hood], seals, gaskets, time, etc and at a minimum purchase a new pump or a restored pump from a reputable dealer. THis will also give you peace of mind and time to enjoy your pool rather than worrying about if you can even use it....just my .02 worth - good luck either way.