Im interested in 1978 300SD that has been sitting for 12 months outside in the rainy pacific northwest.

The car looks clean in and out because it was garage kept and well maintained by the previous owner. Current owner inherited it about a year ago and has started it and run it around the block enough to keep it running and that's it.

My concerns are:

He told me his Dad caulked the sun roof because it leaked. There was water under the rear carpet which is the only place I looked and the car had a mold/mildew odor that could choak a horse. Will I be able rid the car of this problem and smell?

I took it up to over 60mph and all was well for a few miles then there was a kind of low frequency vibration that didn't feel like a suspension issue. The uneven roughness of it made me wonder if it could be a fuel issue. Dirt, water, sludge, gelling, what could happen if most of the same tankful just sat for 12 months?

He pulled the fuse on the radio circut because of a problem.

The trunk lock key would go in and turn, button would push but trunk would not open. Suspect corrosion due to time and moisture.

The color of the oil on the dipstick is black and he has never changed the oil but said it was "clear as a bell" when he got the car.

If all of the above is fixable stuff I have no problem with doing the work.
It's just too bad the guy didn't sell the car the day it came out of the garage. Maybe then it would have qualified as "excellent condition" , but for him to advertise it as that now is far off the mark. He says the price is negotiable but to me it's worth less than half what he's asking, and that may be a tough nut to crack.

Trying to think positive,

Clyde