107 Addict,
Some of the 280SEs of that era use a slightly different fuel pump arrangement from the 113 and the earlier 250SE/280SE. I'm not sure where the cutoff is on these cars, but I've crawled under a number of 280SEs looking for either a small or large style pump only to find that the pump, while a Bosch electric, is unlike either the early or late style pumps we use on the 113s.
George Des