Thanx, amigo --- I appreciate the Input! If you saw the scan, I suspect you'd agree it "looks purty dang good", and next to havin' it in one's hand for Best Inspection (as an Appraiser), that's the best we can do.
I'm willin' to Hope For the Best for my pal, and lean toward this bein' Authentic.
But I won't deny a bit of Surprise that none of youse guys Pegged it as a Good Addy for Leone.
My pal *also* got a sig from another SW celeb (with a heretofore-unknown addy) that ALSO "looks purty good" from a similar/same source. (And on THAT celebrity, I feel *much* more confident, as good as the Leone aspects/provenance were. Also, the Nature of the Sig is such that it's a Very Unlikely "fake" situation.)
I've been in the Collecting market for 30 years (semi-Pro, and another 5-7 before that, Amateur; I'd say I've been close to "Pro" for at least ten years), and so -- as my grandad used to say, "Them thet kin Brag w/o Lyin' ---- LET 'EM BRAG!"

In any case, THANK YOU ALL for your input!!
Best,
DCG.