I have a 1980 450SL with a transmission tag which reads
107 270 02 01
00006665

I am being told by a mercedes service shop that the numbers would indicate that the transmission belongs to a 280 6cyl, not a 450 8 cyl

The car records show that a rebuilt transmission was installed in the car 4 years before I purchased it.

Can you tell from these numbers what car it belongs in?

here is a link to a site that gives number to model application.

Mercedes Transmission application guide