I looked the number up on my Bosch Esitronic CDs and the 032 is the only number in the system. There never was a US 500 with an aux air valve. They went to electronic control of idle for all US aluminum V8s.
I looked in my Bosch info as they do not differentiate the euro from US models and I thought I might find both numbers. Bosch used to make the same part with two different numbers. One had the MB logo on it and was only sold to MB. The other, one diget different, was the same exact part but only had Bosch logos and numbers on it. I can't say for sure as this system should normally ID either number to the same file. It does not show the 033 number at all.
The history of the 032 part shows a number of cars US and otherwise that it fits and the 117.961 fits up to some date in 1981, which also makes sense as the european versions all went to electronic idle control by 1981 sometime.
Bosch Master, ASE Master, L1
33 years MB technician