"Billet" Sporty Pump?

Just picked up a '72 up sporty pump that appears to have been machined from a solid block of Aluminum. No casting marks anywhere. Gears appear to be standard for the era. Anybody have any clues what gives? Was it factory or custom?
Dick

Dick, that sounds likke the ones that V-Twin sells as replacement parts. Been running one for years with no problems (!). G

Thanks for the info GB, is it installed on your K by any chance? just curious.
Dick

Dick, yep it's on my K. The only problem i have is breather problems. Gotta find the time to take the engine out and re-time the breather (PIA). Later breathers timed different than -52 ones. Engine seaps oil everywhere. g