Manx Norton frames

Previously wrote:

Hi, I have just purchased a Manx and would like some pointers regarding the frame and its identity, the Machine has come from overseas and I am advised that is has remained unused since the 80's, the original frame number [if it is] has been overstamped and has a hole drilled through the middle of it making it impossible to determine. Does anyone know how I can tell if it is an original factory Manx frame or a replacement/ replica, it has the oil in l/h top tube and late type rear loop features but I would like to be able to determine its origin. Any advice would be great, thank you.

Hello Well has it a brace plate under the head stock ! Yours AJD