[Mgs] MGA master cylinder bore size - a little OT

[Howard Battan]

Can somebody please tell me the bore size for the MGA brake/clutch master 
cylinder? I have a friend in Ireland with a 1955 Morris Oxford Series 2 car 
who thinks that the brake/master cylinder is the same as that for the MGA, 
and needs a rebuilt or new master cylinder. The unit looks the same as the 
MGA unit, but we would like to confirm the bore sizes to be sure. Or if 
someone can confirm that the units are the same, that would be a great help, 
too.

TIA

Howard Battan