Speaking as a former professional Authenticator, I would say that I see absolutely no reason to suspect the coin's authenticity, and that it does appear to be a genuine partial collar error. I have always considered this type of error to be significant. Should be worth a nice premium.
I'd tell the friend it was a keeper and if they wish to spend more money, have it graded and authenticated.
Where are you buying your analytical equipment? For good lab equipment, you may want to ADD another zero (or at least multiple by 5). Even handheld XRF units are in the 5 figures. @paddyman98 FYI - I've worked for companies that made everything kitchen cookware to aerospace components and have used data from SEM/EDS, XRF, XRD, and occasionally IR Spectroscopy and GC Chromatography. It's not unusual for manufacturing plants to have access to this equipment.
I think it's because most of us are convinced it's real, and a weight and diameter that correspond to a real coin would be fairly weak evidence compared to the clear photos that were posted at the beginning.
And what if it's hallow. I am not opposed to it being real, the question has been asked and not given. Just asking?
I only work with this person on Monday nights. I'll ask him to bring it in next Monday and I'll take a picture of it on a scale for weight and will show diameter with a caliper.
I wouldn't buy it in hand if It wasn't weighed, I almost bought a contemporary 79CC that was just slight of diameter, right on weight, but thicker than usual. Still a premium on the coin either way.
Just chiming in, you'd want to check the weight, and inspect the edge to see if any obvious signs of joining of two coin halves, as you say, you work in a machine shop, I'm sure you know how it's done and how to look for a seem with magnification. that said it displays as legit, the reverse should be the anvil die and that should be the side with the reeding if authentic. base on the pictures I can only get so far though. the edge picture could be closer and clearer. if it's joined, it could test right for metal content. but it likely won't weigh right, and it's very possible to machine down two coins, hammer out the obverse side to make it larger, like making a texas cent and then smoothing the edge down to join the two halves in order to fake this error, but a seam would give it away. it also would be hard to get the weight right if it's a joined coin. the picture just isn't good enough to see the details of it to make a determination if it's legit or monkey business at least not to me it isn't. I'd say it may add $100 to the value on a Morgan dollar circulated examples value, somewhere around there from what I gather, but I'm not a professional or a dealer. Maybe $150-$200 if a couple fight for it and you had it graded to prove it's a partial collar conclusively, otherwise, I don't see it getting quite up there. But again, I'm just a hobbyist. a slab gives it much more credibility to random buyers with interest, and out of slab might keep people away from it when selling it unless they know what they are looking at. People generally trust a slab and will pay more. again, a non-professional opinion.