John, while the Mays on your ball doesn't look quite like the Sweet Spot signed, more recent autographed ball, I wouldn't use the newer signature as an example for direct comparison to older Mays signatures.
That said, I'm of the opinion that the first ball imaged has a forged signature, but based on an older Mays autograph. The M is way off, but looks closer to the 1980s Mays "M" than the newer signature below.