Mercedes classic car for everyday life?

Hello, I would like to know which Mercedes classic cars are in demand and will keep their value in the next few years or even increase them a bit. Background: I happen to see a Mercedes Benz 500 SEL W126 BJ 1981 and a 380 SEC W126 BJ 1982. I really like these two models! However, I don’t know how much these cars are worth with vintage cars and therefore I don’t know how much they are worth. I just don’t want to spend 800-10,000€ on a car that’s actually only worth 2000€. Which Mercedes classic cars are in demand and fit into the mentioned budget? The car should not be a “value investment” but be used daily in everyday life. It would be practically in a dream for me to drive such a vehicle. Is it cost-wise to use an old car in everyday life at all? I know how much the tax with an H-approval costs. I am also aware of the consumption with 12-15L. What about the insurance and the resulting repairs(difference to 10tkm are driven per year. Which models would you recommend to me as an everyday car? Which years of construction? What does it look like with rust problems and are higher running performance a problem? Can you find a good car up to approx. 10,000€? In theory I also find the old Porsche really appealing, but that’s probably the prices beyond good and bad. There are really many questions and I hope you can give me tips.