Hi Dave,
just received some more detailed information on this change.
The steering column hub, together with the wood covered binnacle over the instrument cluster, changed after VIN 088724.
Since the last 250SE manufactured in 1967 had VIN 089205 that means the last 481 250SE cabrios and cabriolets had the later steering column and a leather covered binnacle. During 1967 1,407 250SE (W111) and 55 280SE (W111) cars were made. If we assume that the last 250SE/C was made at the beginning of December 1967, and a linear production schedule of 128 cars per month, then that would put the change-over into July 1967, indeed the same month when the change for 250SL happened.
For what it is worth, I also found out that before VIN 085398 the 250SE/C cars had the M129.II-129.981 engine, after that the M129.I-129.980 engine was installed. That means that the later ones (probably after May 1966) with the 980 engine do not have the mechanical tachometer drive but the earlier ones do.
