Technical Evans heads

Hi. What does the evans heads combustion chamber originally look like? I have these old evans on my 59a and thinking if they are milled too many times, heres a picture of one head with best gasket big bore gasket.

There is about 5 millimeter flat spot around the combustion chamber, is that normal, or should the round shape continue to the gasket edge.

thanks, ossi

 

Usually heads were domed to about 3-5/16" for use on those big bore engines. I'd say yours have been milled.