FYI when Gibson bought out Epiphone in 1957 they acquired a lot of the spare parts and works-in-progress from the former New York operation (at least the ones that weren't discovered in an upstate NY warehouse and torched
), and it's generally accepted that Gibson was producing Epi archtops with leftover New York parts (including pre-assembled but unfinished bodies) through at least late-1963/early-1964. While the equivalent Gibson L-50 is fairly easy to find, Epiphone Zeniths from the post-acquisition period are rare, and the fact that the only two I've ever seen in person over the last six decades were clearly built on the L-50 platform (as I'm sure you're aware New York Epi-designed acoustic archtops have very different body contours than their Gibson equivalents, as well as distinctive carving/arching/recurve patterns), their very low production numbers lead me to believe that yours might in fact be built on a genuine New York body (FYI while the fingerboard was featured on the contemporary Sorrento, it first appeared on the circa-1950 Devon 17" acoustic archtop, and may also be of New York-era origin); if it is in fact a New York leftover it's certainly one of the last (if not
the last), and if it were me I'd have an expert examine it and confirm the details...
Here's an original '49 NY Zenith for comparison (note the smaller upper bouts compared to an L-50 - the slightly wider waist and narrow pickguard on yours were also typical of post-1954 New York production):
Use it well, often, and - as was characteristic of New York Epis - LOUD ...
