Hi Johny, thanks for your thoughts that this master cylinder looks like a GMC150 from an MGB.
I was just wondering, if I do change the cylinder and go back to the original GMC224, would the push rod from the pedal be the same?
Just noticed that the replacement ones say the push rod is not supplied and must re-use the old one, which is OK if it's the same but obviously a problem if it's not.