I have a dumb question: Does these valves fit the 15" Fuchs wheels (126 400 2202) ? It does not look like that to me. I have had both wheels and valves for more than ten years waiting for me to finish my W108.
There are NO dumb questions.
Rims with a 126xxx xxxx part number require standard rubber valves (or the non-specific metal valves). The special valves as bescribed in this thread here are only for the wheels starting with a 108 part number, these are the early bunt wheels (as they are called in the US of A). Late 14 inch and 15 inch bunt wheels usually have a part number beginning with 126, indicating their release together with the W126.