Ok so iv bee for a proper look and it’s not as clean as I remember...the 2 really rusty sections under seem to be a rear outrigger and another bracket but I can’t remember what it’s for.
You could chase your tail and patch it up, but realistically that's a new chassis all day long.
I'd offer 3k for it, and just factor in a new chassis, axle refurbs ie new seals, swivels bearings, pinion seals, brakes, probably steering box, new bushes all round...
I bought my td5 90 for 5k knowing it needed a new xmember and tub outrigger, with 100k on the clock.
I refurbed both axles and drove her for a few months, then I noticed the tubular outrigger needed a patch...or so I thought... They looked in better knick than your one, went of the chassis with a pointed welding hammer until it looked like cheese grater!!
One new marsland chassis later, plus poly bushed and new steering box all new brakes and brake lines, it's been the best and most reliable vehicle I've ever owned, I did all the work myself and could probably (not counting labour for myself) return a small profit if I ever sold it! I won't ever though.
You have to really want one, and know that they are almost rolling restorations until you get to the nice point where virtually everything is done. I still have to-do lists, like screen frame seals, tub seals etc, but they are as and when! Mines an everydayer, plus weekend greenlaner.
I do engine oil and filters every 5k, and tranny and diffs every 8k. I have an ashcroft ATB in the rear axle, and soon to put one up front. They are unbelievable vehicles but you really really have to WANT one!
Looking forward to the chassis swap fread!