The first W123s were available with a 5-spd manual, type 717000. It was used until 1979-ish on such cars as the 230, 250, 240D, 280, 280E and 300D. It could also be used on the 200, 200D and 220D, but I'm not sure it was. IIRC, it had a very short OD ratio of 0.89:1
In 1979, MB used two mechanical identical, but geometrically different, 5-spd manuals: 717400 for the 280E, 240D and 300D, and 717401 for the M102-powered 200 and 230E. There were also 717402, used in the R107 and W126 with M110 engines, which differs from 717400 by having an electric encoder instead of a mechanical speedo cable. All of these had an OD ratio of 0.83, I believe. When the M103 replaced the M110, MB's own new generation of 5-spd manuals replaced the 71740x.
(Sadly, the new MB 5-speeds were related to the new 4-speed manuals MB started manufacturing and introducing in 1979: 716210 for M110, OM616 and OM617; 716211 for M102. These 5-speeds would be introduced on the 190E and on the W124-series, 5 years after the 4-speeds. It stands to reason that, since both bell housing patterns were available for the 4-speed manuals, both could also have been made available for the 5-speeds. Why, MB? Why...?)