ignition switch mount?

Can someone help me indentify wether or not this part should be on my st70? I think it was where the ignition switch was mounted. But on all the st's I've looked at, the switch seems to me mounted strict into the whole in the frame? Anyone know

Hi
I have a 1969 UK ST70 and a 1975 UK ST70 and both have the ignition switch mounted directly into the hole in the frame, also must be earthed to the frame for it to run.

Me too. Switch located in frame left hand side towards the steering stem. The switch then earths through the frame.
Pete.

Cheers guys, think this must have been added from another model for some reason

Its from a cd175