I rather long for the days when I could buy a water pump for my 77 Celica for $36.98 and install it myself in a couple of hours.
Of course, a MB water pump is made better and will propably outlast two or three Toyota waterpumps. Mine had 180K miles on it when it combined with the atmosphere, the last 140K were my miles and I replaced the waterpump twice.
Admitedly, I had a sore back for a couple of days, and I think I usually skinned a knuckle as well.
I throw a can of water pump lubricant/ anti-rust in my radiator every year. That seems to make them last longer. There is nothing in it that could clog anything and I am assuming that it replaces the chemicals that gradually get combined with the metals of the radiator and block.
After 4 years, my anti-freeze looked just like new: no rust at all.
Good luck with your car and new water pump.
Semibodacious Transmogrifications a Specialty
1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)
"Time flies like and arrow, yet fruit flies like a banana"