Mr. Bill, I just had the same question for myself and finally came to a conclusion. The MB dealer had "rebuild kits" for $47.00 each. I found rebuilt calipers for $35.00 each, so I ordered them.. and will have them installed on Wednesday. I do believe mine are ATX though.. so I hope this helps.
1982 300D (266,001 mi.) looking and running great
1976 450 SLC
1982 Jaguar XJ6 (loved, but gone)