Where exactly should the d-ring be mounted on a Linhof?

[Funky]

My research shows that Luke’s droid caller has the d-ring mounted through the rectangular, silver connector clip and the other school of thought shows that the d-ring is mounded through the bulb cover. Does anyone know for sure where the ring where the ring should properly be mounted?

 

[Cameron]

Because of how it hangs off of the belt I calculated Bulb Cover.

 

[Funky]

Yeah, I’m thinking you’re right.
So, in my research, now I come to find out if the rectangular clamp piece is present or missing?