As far as I can recall, the early scenario was basically what eventually evolved into the episode
'The Neutral Zone', with the plot being the Enterprise-D finding a ship with a bunch of people from the past in suspended animation, one of them being Harry Mudd. This was indeed from the very early conceptual stages of
The Next Generation, before Carmel's death saw them rethink the idea (ultimately resurrecting it, alongside the Romulans, for the first season finale).
Quite a few of the 'early outlines' of TNG first season episodes featured more explicit links to TOS and her crew. Only
'The Naked Now' really reflects that in the finished season as aired, but for just one example,
'Code of Honor' originally was about a planet visited (in an off screen adventure) by Kirk and his crew, who still held a blood vengeance for the people of the USS Enterprise for something Kirk had done 100 years before, and to which they still held the crew of the new Enterprise responsible. Which on paper sounds hella more interesting than what we eventually got instead