Looking at '85 300D. Help me come up with an intelligent offer please.

[Kynetx]

I have had a couple of diesel VWs and have always loved diesel. I got out of i a couple of years ago and I've got Rudolph's Syndrome (feel free to use it. $5.99 per use) pretty bad.
I bought a Scirocco a while back and was planning on doing a TD swap into it eventually, but the motors are prohibitively expensive, so I'm driving it with the gas engine.
Yesterday I was driving past a dealership in the area and spotted a metallic blue '85 300D. My wife and I pulled in and the dealer let me poke around in it.

The good:
The engine idles well and starts immediately, even cold.
Decent rubber
Factory power sunroof, works
Power windows that work
Suspension and brakes seem OK
A/C, condition unknown (see below)
Paint is intact with extensive oxidation on the hood and trunk.
No rust
Engine bay seems un-tampered with. Nothing looks to be obviously missing
Doesn't seem like it's ever been wrecked.
It's German.
It's a tank.


The bad:
Gutless. I don't really know what these things should be making for power so I don't have a reference point.
Throttle does next to nothing until it hits the floor, then not much more at that.
Transmission shifts HARD. Far above and beyond what I'd call reasonable.
Stereo system was forcefully removed. Climate controls were probably damaged because the dash fan seems inoperative. Can't test the A/C.
I couldn't hear the turbo spool, so I have no idea if it's functional.
Rear seat has been removed and not reinstalled, could need some work.
Trunk stuck shut. From what I've read it's an easy fix but I'm not going to educate him.
Seat belt on the driver's seat is inoperative/damaged.



All in all, not too bad really. The only things that worry me are the tranny and the lack of power, unless that's normal. What would be a good baseline and what is the highest I should go?

One more thing... Can one change the turbo to something bigger? Is it reasonably easy to add an intercooler? Can I disable the LDA on the fly to make it run lean on the highway?

Many thanks in advance.