Indicator problem

I am in the process of installing the indicators into a steering column for my Manx SR.

It's a long column from a pre 1970s Beetle.

They work well until I tighten the screws that hold them in the column. I can tighten the bottom left screw, but simply by carefully tightning any of the other screws, they either won't work or they work when the swich is turned on a bit, then stop or flicker when the switch is turned fully on.

I have no intention of pulling the indicators apart as I have never been able to get one together again. I have squirted it with WD, which helped, but didn't solve the problem.

Can anyone suggest a solution to this ?

As a matter of interest. I solved the problem by fitting a different steering column head to the other parts. The old head must have been distorted, which distorted the chassis plate of the indicator switch making it not work when it was screwed down tightly. The old head is now in the metals scrap bin.