Girling Brake Master Cylinder bore diameter?

[BioBa]

Does anybody know the bore of the standard Radical Girling brake master cylinder? The options are 0.625, 0.7 or 0.75.

[SportsLibre]

On my early Clubsport the two cylinders for the front and rear are different sizes. It will likely depend upon which calipers are fitted. It may be difficult to read but it should be marked on the outside of the cylinder.

[minitici]

One of Sportslibre's master cylinders was 0.7" the other was the much larger 13/16" (not easy to find in UK!)