Are there not two separate issues here?
The POH (for any modern-ish aircraft) should have a list of equipment which is required under the TC. For light piston GA, day VFR, this tends to be mostly basic stuff like the ASI and some engine instruments. For night VFR, it will be more stuff... For IFR, more again.
The "MEL" issue concerns how much of the stuff actually installed can be duff and you can still depart. This is obviously relevant to commercial (AOC) ops, where the intention is to prevent somebody gaining a competitive advantage by operating dangerous wreckage. It's the same with JAR/EASA OPS and weather minima; an operator who gets in or out under the minima is going to be getting a competitive advantage (so long as they don't kill too many passengers).
On any aircraft operated under an AOC, there is likely to be an MEL of some sort, referenced to the CAA-approved company ops manual. But AOC ops are not exactly "private flying".