Very cool looking but it's an odd mix of TOS and the movie refit designs and as Phase pointed out it is very "Buck Rogers". Still a well made model though.
Well, given that the Enterprise was well over 13 years old at the time of "The Menagerie", this ship could still be post-E and be within the TOS timeframe. Perhaps shortly before they started making TMP-style changes to design.
I likes it. If the nacelle fins were changed that would eliminate the "Buck Rogers" reactions, although I like them.