Did a search and found an earlier discussion on this:
www.benzworld.org
More here: Full throttle , Shift points , vacuum modulator ...
I have a 1972 Technical Data Manual - It gives the shift points for the 107.044 with W3A040 Transmission. I may have included those in first link above.

What RPM does your 450Sl shift into 3rd?
If left in auto my shifts at 4500 RPM even when driven con-brio.... Yours?
More here: Full throttle , Shift points , vacuum modulator ...
I have a 1972 Technical Data Manual - It gives the shift points for the 107.044 with W3A040 Transmission. I may have included those in first link above.