Thanks both of you. Sry for the late reply.. I was having coolant leakage issues and was stressed about the intake gasket.. Turns out it was just a hose
... So the rusty quarter panel is back to the top of my list of things to do with the car. I see now why the quarter panel is so difficult to replace. Too bad it's such a complicated piece.. and from what I can see for basically no reason...
It's mostly just an eyesore as there is absolutely no rust on the rest of the sheet metal so I will be doing something. When the weather warms up a bit I'll probably do what dwalmop ended up doing.
Thanks again,