Help to identify this compressor

I have a 1984 Compair-Kellog compressor that I'm trying to find parts to rebuild the pump. Doing a search on line I can not find any information on this unit. It was built in 1984 And the model number is B451 4BL. It stil in use but it has a hard time keeping up with my sand blast cabinet which requires 12 CFM @90.
Any help would be appreciated------Roy