missing piece from a brake handle, Can't find what part is missing

Hi all,

I have one of these last pieces to finish my 125/2 '58. I have this original brake handle I wan to use, but I can see that there is a space for some sort of plate, but I can't find what should it look like. It is probably used to loosen or tighten the gas handle. Do you have any idea if I can get it somewhere or how to make it on my own?

Thanks a lot for your help!

Angefügtes Bild

Hello

I think you need this Part: " Klick on me"

Excellent! That is what I was looking for

Thanks