Its an F model. It probably is not economical to rebuild it but the blade setup is not common on 22s and from the lack of hydraulic lines coming from the back it must be a front pump or the even rarer pump that goes in the generator spot. Cant tell with the weeds in the way, but look for a PTO on the back. Horrible project but a good parts machine. Just my opinion. Grant.
pump is belt driven on left side of engine