LOL OK, I'll give it a go...
The '75 300D is mechanically very much like the subsequent evolution of the car, since it has basically the same OM617 engine. If you reference the later model (123 chassis) cars on this forum, much of the same information should apply.
No, these are not quick cars but they are very robust, at least mechanically. A "rust free" example of a 114/115 chassis (in this case a 115) is very rare, as the floorboards and fender lips, as well as door bottoms were prone to rusting. Be sure to look at these areas closely before buying, and don't be afraid to lift the floormats and the thick padding under them to see the floor from the inside as well. Also inspect the trunk areas, looking underneath that mat as well.
If all things are as you describe, then it could be a very nice, reliable car. Should you buy it, be sure to keep after the rust prone areas that I mentioned by keeping all the drains and fender wells/lips clean. Some people even recommend replacing the screws that secure the trim pieces at the lower fender wells with stainless hardware as well as a dab of sealant, as this is often where the rust starts.
Please don't ask if the price is fair, as nobody here has likely seen the car and the ultimate question is of what it is worth to you. That said, a classic benz with low miles and in good preservation will likely bring you years of enjoyment.
\'87 Mer-B 300D (220,000 miles) (sold)
\'93 Mer-B 300D (173,000 miles) (sold)
\'87 Porsche 928 (101,000 miles)
\'98 Dodge Ram quad-cab (250,000 miles)
\'2001 CLK430 Cabrio (50,000 miles)
Past cars: 1969 mercedes 250, 1981 300D, 1972 220D