Well, it seems that I've come to the party, fashionably late… FWIW, here's an answer, of sorts, to the original post.
For the green Sevens, Myford used Trimite 2-pack polyurethane. Nasty stuff, because of isocyanates, and I don't think Joe Public could get the stuff easily (safety gnomes at work). When I toured the factory in the '90s, I possibly also saw 10s being painted, but I can't remember noticing the paint used.
I had some things professionally painted hammered silver-grey, and IIRC, that was Trimite too. I've a nasty feeling that Trimite is no more. Perhaps a name change?
I always found Hammerite to be a disappointment. Ghastly to apply by brush, poisonous to spray, and spraying never seemed to result in anything resembling a proper hammered finish. Also, it was brittle and not at all durable. I can't believe Myford would have used it.
Rustoleum do/did rattle-cans of hammered finish paint. A thread elsewhere said that a green ('olive green'?) was a reasonable match for Emco's original Unimat green. Sadly, as far as NZ is concerned, that colour seems to be locally known as Unobtainium. Bother!