Forgot to mention, although there is no Curtis data plate on the controller, it appears identical to the Curtis model 1234E (enclosure design and terminal layout identical), so that's probably what it is.

As an aside, someone at the dealership mentioned a new controller would cost 2 or 3 thousand dollars. But now that I know what it almost certainly is I see the price for the 1234E- 24 volt is actually only $587.50 from Curtis distributors. Obviously, wholesale price to Jungheinrich would be even less.