Dieser schlussel is nur schoen, aber arbeited nieder in dies auto. Excuse my German!
I dont know if the 190 ever had a remote in 92, my 140 remote is one button and was huge for my 92 SEL, they subsequently went to another smaller one in 94/5. I think the 129 SL was the first to use one in 91 and was made by Siemens. There have been at least six generations of remotes with the smart key and the wallet cards the latest. I think some of the very early remotes with keys could be coded in, and that is not a guarantee. The (my) ML replacement remote had to be activated by MB with the HHT.
The only thing those MB remotes on e-bay are good for is status symbols, and replacing a worn housing.