No expertise on 129s--but I can tell you what I've learned from my few months with my 560SL.
It's my daily driver for this summer, and I wouldn't have it any other way. It's much too sweet in use to sit in the garage; it turns a weekday drive home from work into "Damn, I love this car!"
Having said that, I understand perfectly your reluctance to drive your 107, untouched and low-mileage as it is. At that mileage and in that condition, it's a collector car, not a driver, as you've justly concluded.
I'll mention that mine just turned 149K today, runs beautifully and looks great with just enough patina to show that it's used and enjoyed.
Should I say I love high-mileage cars?
