How to test the turbo?

Vehicle is '85 300 TD (wagon) Turbodiesel sitting in one of those donated car lots. Price $1000. I was allowed to drive it around the large lot only. It started okay, but accelerated slowly (without being in gear). In gear it seemed to accelerate slowly, I could floor it for about 2 seconds and I'm sure no one noticed. It did shift into second gear. Body borders on salvage yard , some rust, definate paint job needed, chrome is flaking off....
How do I determine the running condition of the turbo? I never heard any turbo whine, even when turning off the engine. Should I? . The pluses; no dark exhaust smoke at all and mileage at 137k .
A bad turbo is just not something I want to deal with. North

These aren't the fastest cars on the planet, so don't be wary of the slow acceleration. The turbos are durable, but to really test them, you need to install a boost gauge and load the engine to see what it's doing. 1k for what seems like a rusty Benz is no deal, if you ask me.

I did pass on it. I went by the lot last week and it was gone, fine by me. I looked around for the answer on the net about testing the turbo, I seem to recall reading a bad turbo generally will leak oil through the seals, so alot of black exhaust could be from a leaky turbo. I was hoping for an easy check that didn't require tools. I suppose most cars would have a turbo boost guage. (This one didn't).