Paint Question: Should I...

IMO the advice above about whether it is a "rare" car or not is the best so far.
If it was something really rare and special with few similar surviving, then keeping it very close to factory would definately increase it's value.

It is a nice car (even in that gold colour, IMO), but if you intend to keep it, then it's you that you need to please. Red is a popular colour (as someone else has pointed out), but then that will eventually (when you do sell) increase your share of the potential buyers, eh?
If it was mine I would go for the red - I too like red - it's eyecatching - and it suits the '60's cars IMO.
Yep - IT'S YOUR CHOICE !
Good luck whichever way you go and keep us posted.