There is supposed to be a tag on the Turbo that has the information. The Tag is somewhere on the Aluminum Plate that bots onto the Bearing housing.

My year and model most of the Turbos were Garrett (Air Research) Turbos but some were made by a company KKK. The KKK logo is a Triangle with 3 Ks inside of it.

I don't know if they used any KKKs on your year and model.

In the picture is to give you some idea of the Tag. However, on some turbos the Tag is smaller. The tag may or may not be in a position where it is easy to see.

The red arrow in the 2nd pic only indicates which side and the Plate that the Tag will be found on not the exact position of the Tag.

Garrett (Air Research) also sometimes puts the company name on the aluminum compressor housing.
Until I was on the Mercedes Forum I thought that Garrett (Air Research) was an American company in America. I did not know it was world wide. Most of the US Turbocharged cars and a whole lot of big rig diesels have Garrett (Air Research) Turbos.

Attached Thumbnails

   

__________________
84 300D, 82 Volvo 244Gl Diesel