Old compressor hep

George Jets said
Unscrew those 2 reed valve plates, light wire brush them. Then throw them in a tub of white vinegar over night.

Rinse them down with distilled water then polish them up with WD-40 and a Scotch Brite pad, then reassemble.

Good to Go . . .

That will probably work. I would try it first.

But Brian is also right. You can even get Harbor Freight's version of that pump.