190E vs. 420SEL

Gentlemen, I have a quandary.

I have an opportunity to obtain a well-maintained 1986 420SEL with 110,000 miles on it for a reasonable price. I currently own a 1988 190E with 127,000 miles on it which I have had for 2 years. It is an either/or situation (keep the 190E, or sell it and buy the 420SEL) and this is the car my wife will be driving.

I realize the 420SEL is a much more "valuable" car but I am on a limited budget and can only afford Mercedes vehicles if I do much of the maintenance myself.

I have found the 190E to be a relatively straightforward car and have already replaced brakes, water pump, radiator, A/C condenser, muffler, belt tensioner, and various other items myself without too much difficulty. Would the same be able to be said for the 420SEL, or am I getting in over my head if I intend to do maintenance myself.

What is the relative service history for the 420SEL? Good/bad/normal?

I realize some costs will go up such as fuel consumption, insurance, etc.

Opinions?