The pump is K-Jet specific. I'd leave it alone. A generic will not cut it and the OE ones are expensive. The accumulator will leak out whatever gas is in the lines and in the canister. It won't drain the tank onto you. Prepare for a spill but not a flood. It's pretty straightforward how to replace the accumulator.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]