side frame rust through/rot

[RETed]

I wouldn't bother and throw that chassis away...

You claim the car is rare, but I think it's more the fact that you're not willing to look farther for a better chassis.
Chassis' are cheap.
Just look at the classifieds, eBay, or Craigslist - just to name a few options.
Sure, it's not in your neighborhood, but how much does it cost to truck the car to you?
I mean I live in Hawaii, surrounded by water, and I'd be willing to pay good money for a good chassis - it's still going to cost $1,500 from the east coast shipped to my door, but I would be willing to pay for it.

The pics look like the unibody is compromised.
I wouldn't bother with trying to "fix" it.
Cage the car and be done with it.
If the hole bothers you, then just cover it up.
Trying to fix it and getting back the original strength of the unibody is a PITA and basically takes a certified auto body person to take care of the repairs - read: BIG BUCKS.


-Ted