Its always been my opinion that MB did itself a big disservice to itself in the 1960s but not offering a medium-sized V8 to its regular cars.... I bet many potential finny and W108 (prior to the 280SE 3.5 and 4.5) buyers felt the big inline six cylinder on offer was competent, but hardly white knuckle inducing.
The W108 280SE and SEL 4.5 experience in the USA proved far beyond expectations how much the market would accept a normal sized MB with a V8...and a normal price tag. The 280SE/L 4.5 was only on the market for like 2 years but sold in staggering numbers.
Fortunately for us W116 fans MB had a major change in thinking about what should power a normal-sized normal-priced sedan and made the 116 with 3 V8 offerings and only two 6-cyl offerings.