The frame rust looks pretty bad. You would have to take a wire brush to it and clean it good to see exactly how bad. The entire rear section of the frame on that side may need to be replaced or patched. After you clean it and stop the rust you may be able to live with it for a little while, but I would not tow anything.

If it has to be fixed I would imagine it is not going to be cheap. A piece will have to fabricated to weld in place or that section of frame will have to be cut from a donor and welded in.

 

x2. Once you get the truck up to snuff, you'll just have to be extra diligent about addressing each issue as it comes up. My experience has been that as long you take care of your Rover, it will take care of you.

That said, what 'binvanna' is saying isn't necessarily bad advice, but as long as you're going into it with your eyes wide open and your determination doesn't waiver, you'll be able to make do.