BEFORE IMAGES:
Part One:
RUST.
As I did mention in the OP, the car was incredibly straight in the problem areas, but isn't perfect.
Here are some of the crusty bits that I'm working on getting repaired before I do anything mechanical. Step 1 in making a car last forever is to make sure the platform is solid before wasting money on go fast parts.

FUEL FILLER DOOR:
There's some minor crust in the bottom RH corner of the filler door, which a previous owner has tried to stop from getting worse. The part that perplexes me, is the riveted on stainless plate. I suspect that's also concealing some rust as well, but some cars did come with these kind of things factory. There might not be rust under there, but at some point an owner has attached the frankly hideous plate to the car.

RH REAR WHEEL ARCH:
There's crust spots along the outer edge of the right hand rear wheel arch, some has been painted, some hasn't, I suspect it goes a fair bit further than it looks like it does, but as far as panel rust goes this is the largest section of it.

RH REAR QUARTER GLASS SILL:
This suspicious riveted stainless plate (lined with silicone), very similar to the one near the fuel cap, lines the entire lower half of the rear quarter glass. Best case scenario is previous owner thought lining the whole sill after some paint loss looked better than just patching up a problem spot.
Worst case, the guy let it rot for too long and the plate covers rust along the whole sill. being that its silicone sealed, I believe it can't have gotten much worse since it was "repaired."

RADIO ANTENNA MOUNT:
Not entirely sure how this one happened, and not entirely sure what I'm going to do about it. Patrly I want to just shave the antenna off altogether and make the panel look nicer once the rust is gone, but in saying that I never know if/when I may need AM/FM radio. Minor crust, not too worried about that one.

LH REAR QUARTER GLASS SILL:
This is my biggest worry as far as this car's body goes. The crust has actually developed a hole, and rain/moisture gets in easily. Was never attempted to be repaired during previous owners' tenures. Best case scenario: fixing this hole makes it go away. Worst case scenario: the whole quarter may be compromised. We shall see.

FRONT WINSHIELD MOULDING - LOWER:
This one seems to be my easiest fix. It's crusted all the way through, but the entire panel is available online to purchase. With any luck the crust will have started and ended on this panel and have not also compromised the windshield cowl panel underneath.

LH FRONT RADIATOR SUPPORT:
This subframe has some rust, only on the left front corner of the car, seems to be the only crusty structural component.

LH REAR QUARTER PANEL:
This one stumps me. It's two minor dots on the rear quarter, that I can't think of a way they appeared. Both had attempted repairs, and I'm not too worried about it.

BONNET/HOOD UNDERSIDE:
Someone has slapped some anti-corrosion patches from repco on the underside of my hood. unsure if it means there's rust under there, but the entire hood will likely be replaced before I'm finished with the car, as the spot welds on the support bracketry are starting to pop out. Not worried about this one.
That's it for the rust, moving on to my next post which will be about other minor body damage.