I am restoring my father-in-laws 1948 S7 Sunbeam. Two things were in bad shape, the gas tank and the rockers arms and followers were worn. I have the tank being restored, thankfully and a machine shop looking at the rocker arm repair. What I need is the original profile for the rocker arm contact. One of the four arms shows severe wear, and we are planning to match the one to the other three but was hoping for original design details. Can anyone assist on the contact profile specifications?