Can anyone out there supply any help on this one - I have what looks to be a cannonball - NO FUSE HOLE - Ball is Hollow and made in 2 halves - Roughly 6" Dia. - Ball Splits in half by means of one 5-7/8" long set screw - Marked on the inside wall of one half of ball it has -- MOD. 500 and N0. 14-16-18 -- and some other reading that appears to read ?FRONT?&? BACK BALL - The other half of ball on inside wall has only C83 - Ball on outside appears to be iron and is magnetic - Looking at inside it looks to be BRASS in color but is still magnetic - each half of ball has a pair of ears on inside rim edge that are lineup pins for assembling the 2 halves together - Weights roughly 4 pounds and walls roughly 3/16" thick. Appreciate any comments. Could supply and send some photos if need! THANKS FOR YOUR TIME IN ADVANCE!