"New" '81 300SD

[cbeaner007]

Hi Guys,
I just picked up a 1981 300SD with only 75,782 documented miles. I have full maintenance records since new and it really is a one owner car. It belonged to an elderly lady whose husband used to drive it, but after his death in 1989, she bareley drove it. Carfax was completely clean and literally everything on the car is original to include the Becker Europa Cassette stereo. Even the cruise control works. I ended up paying $9500.00 for the car...did I do OK?

I have only owned 1990's E type diesels in the past so I was wondering what the general forum opinion on this particular model might be. Also are there any particular items I should have checked or watch out for with this car.

The only defects I can find so far are as follows:
1) Tachometer not working-where is the tach sender on this car?
2) There is some growling when backing up slowly, maybe a drive shaft carrier bearing. Doesn't sound like a wheel bearing. Might be a CV joint...any other ideas. Transmission shifts well, doesn't seem to be trans at all. It does have a "clicking" component to it.
3) Instrument panel lamps not working. It's not fuse related. I haven't pulled the instrument cluster to look for loose connections, etc.
4) AC not working. Previous owner told me the climate control module needed to be replaced. Freon was recharged in May and it was working at that time. Is is common to need to replace this?

As always, thanks for any and all help!

CW