I need to cut a brand new firewall for a 1918 from a piece of plywood and need some pretty complete dimensions. I can find several diagrams on the internet, but they only list the width and height. That's fine as far as it goes, but since I have no pattern to go by I need the exact radius of the upper edge (for a low hood/radiator)...and the locations of the coil tube holes would be nice too.
Can anyone provide a diagram or point me in the right direction? Thanks!