This week....
MISSION ONE - replace fuel accumulator, fuel filter, fuel damper, fuel flex line into chassis fuel rail, fuel outlet line from fuel tank to fuel damper (do check these as my old 280SEL dropped a whole tank of fuel as was way past its service life, fuel line that is) , replace fuel pipe between fuel damper and fuel pump, replace the 4 rubber mounts for fuel assembly.
OUTCOME - looks good, the fuel damper and accumulator are now retro parted to W126 parts so accumulator a lot larger resulting in near silent fuel pump running, all else standard. Parts not supplied but essential are copper washers between fuel pump and fuel filter, don't even think of recycling used ones, part number - Copper O-Ring (12x17x1.5mm) - CRP 007603-012110 (can also use for oil drain plug if you don't have the tapered one). New pipe clamps for the fuel hose from the fuel tank and the hose between the damper and fuel pump are 12mm to 20mm clamps. Fuel hose between fuel damper and fuel pump - 1234763026 CRP-Contitech OEM - Fuel Hose/Line; Damper Cage to Fuel Pump; Reinforced; 14mm ID. No major issues, as was replacing fuel lines at either end i removed the whole assembly which made access to the mentioned fuel lines very easy
NOTE - to help anyone including yourself in years to come if you still have the car, use a permanent marker pen and write the month and year you replaced the fuel pump, fuel accumulator and fuel filter
MISSION TWO - replace the rear mount for differential, not easy and a lot of stuffing around
OUTCOME - eventually, good, but required a set of bolts to drift back into place the mount as supporting with jack only raised the whole flipping car up and down

the two rear bolts to subframe can be a long length but the two front ones require bolts of less length so started with 2 X 90mm then went down to 2 X 50mm with greased washers to reduce ratcheting drag, got there in the end but took all day for what i thought was a 2 hour job
NEW MISSIONS SHOULD I CHOOSE TO ACCEPT IT - door locks not holding vacuum

sun roof cable binding so need to work out how to replace that

G