383 Help/Questions, Long Storage, Unknown Parts

That's probably a sealed power replacement cam. All of their "performance" versions for ChryCo engines have that rubberized paint on them, and it peels off easily. You are absolutely safe to get some oil in it and a blue bottle of STP on the cam to do a compression test. But I'm with Hellrats here. Get a little 20 weight motor oil in the cylinders to bring the rings back and run it. Maybe use a bore scope in the ports and plug holes to determine no accidental debris getting ready to beat a piston to death and run it, get everything freed/cleaned/oiled up/ran back in for the compression test.