Awesome let the fun and games begin
Tell Sally welcome to the Westfalia Syncro club
Where to start Sally? Let me help....
Westfalias although very good have one major week point, the cavity between the outer body work and the inner door cards was filled with fibreglass. It was good enough as the van was built to last 10 years and as most of them are now around the 25 year old mark you will notice all the rust coming out of the seams as a result. You can get it behind the fridge the most as the warm air from the fridge vent condensated and the fibreglass held the moisture near the floor on the inside and you will find that in a van with the obvious tell tale sighns in the eBay ad like yours will have large sections of floor rotted through on the inside. Get Neil to pull that vent cover off behind the fridge (that shouldn't be there anyway and will need welding up

) and put your hand in to feel the pile of metal corn flakes and the long hole running along the inside of the van. Also there is a cross beam running mid way up that big panel and if you can push the side panel in slightly and it does flex then that could be rotted out to.
A good and easy tester for a Westy is to open the back door, take the door card off and pull the fiberglass out and give it a squeeze and see if any water comes out. Then look at the inside of the bottom of the rear door and that's what the inside is like behind the panels.
Next job,
Take all the interior out to see how bad it is. If the photos on eBay are anything to go from over the rear arches (like behind the fridge) are rusty because it's rotting from the inside out. Once the interior is out and you can look and get your hand in expect full panel replacements. Go for good panels and not the cheap ones as they won't fit that good. If there is any rot on the rear door along the bottom of the window on the inside you will have to get one as well as the replacement panels, maybe a sliding door if your un lucky, then the front panel under the windscreen looks like it could do with replacing so that could be a dash out.
Take a look above the rear jacking points for holes or outer repairs. Unlike other sika's, doka's, velle's etc because of the fiberglass thing when the rear jacking points on a Westy go its usually from the inside and require major work. Get Neil to jack the back of the van up and listen very closely in the area for cracking noises. If you hear anything or worst case they go, that will need factoring in.
I would say its about to far gone for a £1000 blow over by Pete and like the add says it does need work so you would at least be expecting all this anyway but once all that's taken care of proppey for hopefully under £4000 you can start on all the bushes, running gear, gearbox, machanical and MOT.
Looking forward to the photos and the work ahead but you should be fine with a £6000 work and parts budget on top of the purchase price to get it safe and straight, then maybe look at putting something with more guts in than that 1.6td, you will be looking at another £5000 on top for that.
Say good bye to any spare cash you had And the best of luck.
Jed