I would like know for the Basic K75 what type of fillister head screws (4 pieces) are used to mount the instrument cluster to the mounting bracket of the headlight unit. Thank you.

According to your Profile, Stavros, what you have is a K75S, not a K75 Basic. Each K75 model can have different mounting methods for certain components. I always go to MaxBMW when I'm trying to identify a part. Others may go to realoem.

Anyway, here's a diagram of what you might have, followed by an image of what you might be seeking.

Laitch thank you for your reply. Almost ten years ago, I replaced the fairing with the basisc headlight and the high bars, (for the city riding). I searched the OEM before my question to the forum but I am a bit confused. If I read correctly the diagram, in the Basic model for the cluster they use 4 hex bolts to fix it to the mount, while in the K75S they are replaced by fillister head screws. I can understand the difference to the lenght of the screw (between the two models) but not the change of type. In the Clymer Manual I only see fillister head screws to various models, (but obviously there are no tech. specs for the parts).

This one of those occasions that provide us the thrill of lower-order risk-taking. Both fasteners use the same washers so my inclination would be to pick the one that has the correct length for the use and cast obsession with the origins of engineering decisions and production costs to the wind. Exciting? 

Laitch this is a wise thought. I will do as such...
Thank you!