Need Advice with Purchase

[Old Charro]

Hello, my first post, but have been reading for a few weeks. My questions are:

Looking at a 85 300D turbo in an EL Paso,TX dealer, 200K+, AZ car no rust. Car runs strong, drives straight, stops smooth, AC cold. Dealer wants $3500

Problems I have found so far are, One of the vents does not blow, and tach does not work.

What else should I look for, I realize this is a 20 year old car, and will have problems and needs attention. Just dont want to get burned.

I'am not new to diesels have 2 older Ford 6.9, and a newer Powerstroke.

Thanks Andy