Hello, I need some info about a Speedmaster 125th. This model is made of integrated bracelet which holds the movement module by a rubber gasket. I wanted to change mine so I opened it, but the old gasket is too damaged to see what is the size and thickness. I tried with sizes but I can't seem to fit anything in there. Can anyone help me with the correct gasket and how to fit? I tried silicon grease but still no joy...