So where has it been all this time? I seriously doubt that this is the original. After reading about the guy that scammed a lot of people building fake "original" communicators, even with "letters of authenticity" this smells of something similar. The pictures shown don't look like a 45+ year old prop, it looks fairly new.
The article says it's been kept in storage in its case since after the pilot, which is why it was never reused. So it would still be in pretty good condition. But the close-up photos show that it still has a lot of scratches, probably from shooting.
And the sticker on it looks awful modern to me. "M-94A" with a serial number?
Why does that number seem modern? If you're thinking it's by analogy with the M16 rifle, that was adopted by the USAF in 1962.
It's not a sticker, anyway; it looks to me like a metal plate, and it and the font seem consistent with the period. The materials look period-consistent too, including the repurposed parts -- the sight on top is a standard telescoping TV/radio antenna, and the lights on the right side look like Christmas-tree bulbs, maybe. And the color and texture of the body looks consistent with '60s materials to me.
Anyway, it's an interesting prop design. I like the three color-coded chambers, which apparently can be rotated into place to switch settings. I guess the colored squares on the back are meant to be buttons for selecting the settings, but I seem to remember seeing Kirk rotate the chambers manually at one point.