Mercedes Benz repair: towing, diesel benz, wind resistance

Question
i have a 1983 diesel Benz 300TDt i've got it running on heated waste food oil.
I've thought of towing X-country is this transmission worthy ; any other concerns?

Answer
What cargo/trailer total weight, and tongue weight?

A total cargo and trailer weight of 1000 pounds with trailer tongue weight of 50 - 150 pounds should not do damage.

Wind resistance varies as the square of the relative wind speed.
If it is not aerodynamic; you will suffer cube square wind resistance speed/MPG loss, especially at highway speeds, also possible steering/control reduction.

Without a full hands on inspection of your vehicle, this is the best I can answer your question.