Purchase advice: W116 or W126?

Hello people! I would like to buy a Mercedes Old-/youngtimer soon and have set myself on a mercedes S-class between 75′ and 90. However, I can not yet decide between W116 and W126. My budget is quite limited (350€), however, I have been screwing with uncles and friends on cars and motorcycles for years, which means that I can also make repairs myself. Important for me is a correspondingly small engine due to the already high consumption. (260/280/300er) For which of the two vehicles would you decide and why? Experience reports, weak points, spare parts situation, as well as insurance, tax costs, tips and advice please just post in. I really appreciate you for every info super! Greeting Philipp.