I know, there is no W125.

But, actually, there is. FIL pulled out his old "Sounds of the Grand Prix" album from the early 1960s... it jogged my memory. The 1937 GP M-B was a W125, according to the track listing.

So, for all of you who think the 123/124/126 era was the pinnacle of MB engineering, you may be right. And the elves in Sindelfingen might agree- why else did they number them in sync with the all-conquering GP car of *its* era, the one with HP numbers not matched in F1 for forty years???

Just a random thought.