RX7Club.com - Mazda RX7 Forum - 1985 GSL Update... Frame Rust question?

Here's My experience test driving the GSL, and a question or two:
I arrived a few minutes early, to find the seller trying to get it started. It wouldn't start, so we went to buy some gas.. fired right up after it had gas... :)
and then.. HOLY SMOKE BATMAN!!!! I didn't think that a motor could smoke that much... cleared up after a few seconds though, I guess she ran pretty rich there for a minute
I let it warm up... the automatic choke removal on the motor is pretty cool!
Had to move it pretty fast... it was setting the dead grass underneath it on fire :)
I let it warm up some more, and then took it for a spin.
I took it easy at first, and the had some fun.. this thing really has some guts!
And whoever said that it couldn't lay a patch... well, the two 25 foot black stripes infront of Mike's Mart in tilbury make me think otherwise :)
Clutch felt REALLy strong.. I believe him when he said that it was brand new, I could get a good bit of rubber into 2nd and a bit into 3rd, too
It just amazes me how much rotaries love the RPMS... I shifted at redline quite a few times, and significantly past (8000ish) once or twice... the redline buzzer sounds cool
The owner also had a 1988 Blazer (3.1v6/5spd)... I followed him around at 150+ for a few minutes
then we turned around, and I discovered that the LSD works just fine, as I spun out in the gravel.. . hehehehe, I should have feathered it.
there was very very little low-end on the car, it was driveable below 3000 (I did alot of shifting down low, too, like 1500-2000RPM shifts), but there isn't a whole lot of power (at WOT) till around 3500-4000
I brought the car to redline in 3rd once, VERY VERY smooth... motor sounded like it coulda taken 15,000RPM
I really liked the sound of it too.
Problems I found: Power windows were slow as ass... maybe I can fix that.
Cracked Windshield (didn't notice before, hard to see from outside but will need to be replaced)
The Rust: I checked underneath, on the drivers side most of the rocker panel in the bottom is gone, (to about 4" into the door) the frame feels solid but there is alot of rust on it. I think I'll clean it up and get a big slab o' steel welded to it before I do anything performance wise.
Handling: Not bad, rear end felt a little funky going left, but that's because of the sway bar.
I managed to lose the tail on it once on the pavement, but I was trying to, so that's OK :)
Overall: I loved it. Now I just gotta find the $800 to pay for it!
Well, with an average cheque of $150/week, It should come to me pretty quick.

Questions: Does the frame sound too bad?
How about the rocker panel? How hard to fix? I've never done bodwork before. Also, the drivers side rear fender is nasty, I may replace the whole piece. The parts store said $150 for the panel, should I go that route or find a junkyard one and cut it out? Obviously, I'd have to do some painting, but I dont' care about a showroom finish on this car (yet), so I dont' care, as long as it looks decent from 10 feet away.