I was able to remove the one of the oil cooler hoses (one that goes to the bottom of the cooler) without taking much off other than I think the vacuum line going from the booster to the pump and some fuel lines that where in the way.

YES it is very tight in there. I have a whole new appreciation for working in the engine bay of my w123 after doing that job on my w115. My hands were extremely cut up by the end of the procedure. I did not remove the battery tray. Good luck !