The pump is either MTE or Viking can,t tell from the pics. Replacement parts are usually not worth the material and labor to fix. A new replacement pump will run between 75.00 to 150.00 depending on gpm. All the 2-stage pumps on the market in the same gpm range will work as direct replacements with little or no changes.
Haldex/Barnes, MTE, Viking, IFP, Northern tool, and Speeco 2-stage pumps in the 11 to 16 gpm range use the same industry mounting pattern.
I have not seen any rebuild or parts kits for any of the above mentioned pumps.