I have to disagree here...
Resto can be (as simple as) putting it back to new-like.
Mod is any modification,as long as it is approved by owner..not others..
Restomod.. Your definition. May vary wildly from the next guy..
there is a trend in the automotive hobby called restomod where you take a car, restore it to look mostly stock, but then do a few modern upgrades so it is more reliable/performs better. Think restored stock bodies 1965 GTO with 2006 6.0L modern GTO LS2 and 6 speed trans and Qa1 coil overs at all four corners.
If you want to go to the literal definitions of things that's fine, I prefer the source material and in this case it is car craft/hot rod/popular hotrodding from 15 years ago.
Most of my definitons come from the automotive hobby since they are the larger group and usually drive the lingo. Properly in classic car circles a "restoration" aspires to be a factory correct restoration that is judged on a points scale for accuracy. A RestoMod is a car that looks (mostly) stock but is better than stock. A Hot rod is just that a modified vehicle.
Craigslist uses it's own language and does more to solidify everybody is either a cheat or a moron when they sell something rather than advance the hobby.
Unfortunatly using this logic has it's down sides. A cafe racer is now a poorly amateur built differently shaped chopper owned by a 20-30 something, instead of the street legal road racers I grew up with, and a bobber is just a chopper without ape hangers instead of the flat track rigid race bikes of the 20's thru the 60's.