Let's see ... near stream of conscious thoughts about this:

if you plan on doing near zero work, get / do a compression check first, check the oil for metal debris / regular oil changes, and check that it has good oil pressure. Also checking the gap on cam lobes -- those metal disks for the non-hydraulic lifters are getting a little more pricey to have, and too tight will burn valves, too loose will leave even less horsies to go up hill with.

Some things will need to be done (unless this has been a well-maintained daily driver) -- e.g., injector return lines, fuel lines, wiring harness ends (unless you are really lucky), etc. Not expensive nor difficult, but will likely be needed. Also check resistance on each glow plug separately from the copper bar that joins them, if that and the relay are working, then you shouldn't have electrical problems with starting the car when it's cold. If you do, pop test the injectors. They are also not pricey, and can be rebuilt. German Bosch nozzles if you can get them. Oh, and door handles. You can adapt the later style -- highly recommended, since you're be replacing them a bit if you don't. They were one of the quickest wearing parts.

Probably that's the dasher, which I think is a little on the fugly side; but, please keep in mind, I am a big giant hater.

If you are planning on doing some work, here's some things to think about:

Get a turbo? Yes, especially if you live at any elevation. More power, better economy, less smoke.

The bad news is, you can't just add a different intake, turbo, and exhaust, etc. The block and pistons, etc., are different (the pistons have cutouts in the skirts to make room for the oil cooling jets that are in the turbo blocks). A stock block can be modded to do this, if you replace the pistons with turbos, but the head will be totally different (later style heads are made of a more durable alloy, and some are interchangeable -- ymmv).

The quantum motors came as turbos, a very few of the early jettas came w turbos. You can also pretty easily adapt a slightly later model motor in, and rid yourself of pain that includes shimming the lifters ... the later models are hydraulic. Also, keep an eye out for a 5 speed, it makes the driving experience much nicer if you have much in the way of hills.

Point taken for the person who mentioned getting good at timing injection pumps (a few tools, not pricey, and worth having around -- dial gage, extension, cam lock, inj pump gear lock).

Even if you rebuilt the entire thing, you wouldn't be into it for much, if you shop around for parts on good german (mahle) pistons. Otoh, if you pay someone, you will be looking at a lot of sunk cost -- though it may be a perfectly reasonable investment at an ave of 40 mpg why, 35 city -- with hard driving and hills at elevation. closer to sea level the better performance and so forth.

The suspension system is not super expensive if someone hasn't screwed it up, and I think all of the soft parts are available still (german). Brakes are easy, and tires are not much money, though that size is probably not so common any more.

Alright, that's enough proselytizing for me tonight on the beauties of black sabbath and early VW diesel engines. I've driven quite a few of them, rebuilt or helped rebuild a few as well. Mid-80s volvos came with a rare 6 cal td motor, which was made by VW, and which had some issues, but could be made to be reliable.

Alright. Good luck H.R.