They may be able to work on the older Benz's, but just don't really want to. They're simpler and thus cheaper and a less revenue generating use of their time. I don't deal with the dealer in KC, they're reputation is horrible and I don't want to spend (waste?) the money on their "expertise". But, I know the Porsche shop (connected) discourages working on old 944/951's for the same reason.