Cleaning distributor?

[flbenz]

I've got a 1976 450sl, about 140,000 miles.
I know the fuel distributor is quite sensitive, but does it make sense to replace the o-ring and the valve?
I see there's a "valve kit" at Fastlane for about $50 - seems like the spring and rubber seal are the main things that might go bad.
Better to replace, or just pull and clean out? And can I even pull out that valve without readjustment problems? (same for o-ring question).
Thanks. I'm replacing fuel lines, filter, etc. and cleaning out the whole fuel system, and wonder where to stop.

[mercmad6.3]

Sounds good to me,I have done it myself with very pleasing results.I Use a dentists ultrasonic cleaner to get the best results.The kit is really only neccesary if the valve spindle itself is scratched or otherwise worn.