I think using any vintage car as a daily driver is a "lifestyle" choice. It's doable, but you need to factor in the quirks of having an old car vs a newer, posh, turn-key MB with air conditioning. If you can handle those quirks and you stay very on top of maintenance (which it sounds you will do) and can live with the cramped quarters, all I can say is.....
I'M ENVIOUS!
My Porsches have been the most reliable cars I have owned. My 77 never let me down and my 964 has proven excellent also. The 3.0 SC should outlast your MB even with it's head start in age. If I lived in a warmer climate (someday......someday....sigh) I would make my 911 my DD. Btw-The P/U is a good choice for back-up which you should have.