Won't fit in a 65, the brake booster will occupy the same space as the left valve cover. MB moved the booster over about 3" on the 68 and later W108/109 to accomodate the V8 -- if you have both side by side, you will notice that the clutch and brake pedals have a differend bend to them. On the early ones, they bend to the left, on the later ones they bend to the right. I don't know if you can modify the mounting to get the necessary clearance or not.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!