Found the answer in the M117 manual. They are fuel lines coming from the fuel cooler. Have already disconnected and popped the cover off. Finally a chance to use my metric flare wrenches
Back to work.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.