Looking to restore it.... what should i be looking for in terms of problems?

Congrats, they are wonderful classic cats. Most need saving from Rust. On your car. ..it looks like the rust in the rear quarter could be extensive. They tend to rust from the inside out in that area. It can be fixed and will need reinforcement. I also have well over 400 HP in one of my coups using a SBC with fuel injection and a proper tune for deliverability. Check out my YouTube vids on the repairs in that area, chassis reinforcements, and engine upgrades.

Search you tube for icsamerica jaguar.

Awesome car. Like ICS sez, if you can see the rust in the lower quarter already then it's probably ugly underneath. But, everything is fixable.
Keep your rare Jaguar all Jaguar.

Nice car! Congratulations

Very NIIIIIIICE.

Rare as they come, and as said, all is fixable.

Rust repairs these days is a lot more successful than say 20 years ago. Modern procedures rarely sees it return if done right the first time.

Very nice!!

Can't wait to see it coming along!

There is really serious rust at the back, in front of the rear wheel arch, as expected. Be prepared for a big job repairing this. Reason it gets so bad is Jaguar never really put in proper sill drains to drain away the water that drops down between rear window and the rear quarter. On a 4-door car this water goes into the door and out the drains; the door may rust of course !

What in terms of cost is the worst case scenario to replace all that rust?