W124 Engine/Transmission Number Q's

[ChinaClipper]

I was looking at my 86 300E 5 speed Engine and tranny numbers, (preparing for tranny rebuild) and am trying to clear a thing or two up.... 1) My engine number is 103.983-10-0028XX, does that mean it is an early run? 2) My 5 speed has 126 261 05 21 CAST in the body and 126 260 10 01 STAMPED followed closely by 717.430 00 32 4206. Is the CAST # the part # for the case and the STAMPED # the actual model number? Which is the actual part #??? 3) My motor mounts have seen better days, why is there a pink and a yellow paint spot under the mount? Thanks all Scott BTW ANy good sources for 5 speed tranny parts?