[DLK]

No idea if it still is of interest, but I my 1987 3.2 Targa (G50, US spec) there was a 911.641.301.05 tach. Had a white sticker on the side with the text "Anschluss an Bosch HKZ-anlage Klemme C (Unterbrecher)

This is the version with the "shift up light"

I have replaced it with the ROW version of this tacho without the shift up light.

On the version I removed all but one terminal on the plug had a prong. On the one I use now, there are a lot less prongs present in the plug.

I have pictures of the original one of you want them.