I watched Assignment Earth for the first time in a long time recently and the back door pilot nature of it all really distracted me. I could see where the show might be all right on its own but I wanted it out of Trek.
"Using the lightspeed breakaway factor, the Enterprise has moved back through time to the twentieth century. " -- my ass!
Star Trek: Deep Space K-7. Starring Stanley Adams, William Campbell, and William Schallert as Nilz Barris.
That's what I was thinking.
You could have occasional visits by the Enterprise and the musical numbers would probably be more contemporary than those of DS9.
I could see a fun show made from this if done right.