I don't know that ZAQ2 means anything, but if you wanted to use any of these particular keys on this typewriter you were out of luck, because the Z, A, Q, and 2 keys didn't work.
We didn't have much in the way of nice things when I was growing up, but we did have a really nice typewriter. It was a Royal KMM, and my mother took care of it like it was the finest thing in the world. When it wasn't being used, it sat underneath a cover she had made for it. This typewriter had been manufactured in the 1940's, but even though it had been around a while, it always looked and functioned like new. The Royal KMM model was the same typewriter model used by Pear Buck, Tennessee Williams, Rod Serling, and several other famous writers.
I don't know what ever became of that old typewriter (I think my Dad must have sold it in a garage sale), but for a long time I've kept my eye out for one. A few weeks ago I ran across this one at a flea market, and just had to take it home.
My flea market find had a few problems: (1) the A, Q, 2, and Z keys were frozen -- wouldn't move at all; (2) a link between the Z key key lever and typebar was missing; (3) the platen clutch wouldn't engage (meaning the platen wouldn't index when the carriage was returned); (4) someone had put some sort of shiny, oily liquid on the platen (to make it look shiny & oily looking, I suppose); (5) the ribbon was shot; (6) the bell didn't "ding,"; (7) in some places the paint was chipped off; (8) the margin release didn't work; and (9) the whole unit was filthy.
Other than that it was fine......