That looks like one of the original ones, huh? It's from before Bob Moog got the rights to the "Moog Music" name, which is why it has his signature on the unit and says "Big Briar" on the manual.
I love mine, and am not sure if there are any significant differences in sound between the old ones (which I have) and the new ones, beyond the longer delay times available on the new ones. Less that an hour left on the auction!