MGA 1600 Master Cylinder Rebuild

[Robert Guinness <rjglaw@swbell.net>]

Here are your dumb questions for the day:

1.   Is the MGA 1600 Master Cylinder metal cap supposed to have a vent 
hole in it?
2.   Does the seal under the cap need to be replaced during a rebuild?
3.   If my 1600 has standard back drum brakes and front disc brakes, is 
the brake bore supposed to have the backflow valve in it?  (The Manual 
says yes, but the used master cylinder I bought does not have it)?

Thank you.
-- 
Robert Guinness
'61 MGA