Wants to buy old G.

Since I was a child, I really like the car. However, at the Bundeswehr I was “defeated” about the G and had to drive with the Iltis. Now I want to get an “old” G as a hobby car. Who has experience? How is the life expectancy of a 230 GE? Are the diesel more robust? Is a e.g. 25 years old G still to be used as a everyday car (second car)? Or does it already require a lot of care and love? This is why the diesel/petrol consumption difference should not be so important. Is the car maintenance-friendly? Can a free workshop (former Mercedes Meister) wait for such a car or do you need many special tools? The driving performance is completely irrelevant. I would also need a 240 GD. A 300 GD will certainly leave because of the tax burden. Thank you very much in advance.