You know good steel so handling it should give you an indication on how useful it could be. Some of the manufacturers did actually make a working wrench that size not sure if they were salesman samples or sold as novelties but they come up from time to time.
The Dimalloy would be my pocket choice partly because it's smaller but mostly because it's easier to find the Diamonds than the MACs and the MACs seem to get a premium over the Diamonds.
I used to carry a 4" and made it a keychain charm so I wouldn't loose it. I have a small collection so I'd rotate them every so often.
Maybe I will get lucky and it happens to be a real tool, not counting on it but it would be nice.
I've never even seen another MAC AW4 so I'm sure you're right and it would be best not to loose it, but it's been with me everyday for years and while I think finding a more appropriate option would be nice I'm not sure how I'd feel about reaching into my pocket and feeling a different wrench in there.
Sure it would be better than reaching for this one and discovering that it had been lost, but I always carry it in something. Pocket organizer, belt pouch, you name it the little guy is almost never just loose in my pocket.
I'm starting to think maybe clipping this to my belt loop would he a good way to go, I don't really want to put anything on my keys so I'd have to carry it on it's own, but there's lots of good options out there for carabiners and such.