Hey Windcree. Another P 28-1 owner here. I have read where those footpumps can be repaired but have never tried to do so. Replacing one looks simple enough to me. At least you don't have to do the work of citing, cutting the holes etc. for placement eh? I think you can get one new for around $50. WMs 2009 catalogue has them at $30.
I would play around with fixing one with the money
available to buy new if it can't be done. You never know. Good to know how to do that anyway.
Maybe someone here has worked on one.
Good luck and happy sailing!!