is there a database somewhere with master cylinder sizes ?

im just debating on wether to change my calipers or the master cylinder(s)

so to start of , what sizes do caterham/westfield use ?

Wesfield use a 0.7 mastercylinder on the standard model. Which I think is Mk1 Fiesta 997 & 1100 poverty spec non-servo
http://www.westfield-sportscars.co.uk/shop/product.asp?numRecordPosition=17&P_ID=173&strPageHistory=cat&strKeywords=&SearchFor=&PT _ID=73

http://www.westfield-sportscars.co.uk/shop/product.asp?numRecordPosition=2&P_ID=174&strPageHistory=cat&strKeywords=&SearchFor=&PT_ ID=73

Caterham use Master cylinder Girling part number 74066147 on the standard S3 (prettty sure Morgan used this cylinder and some FX4 Taxis) I have seen the cylinder reported as 11/16" bore but can't be sure.

Caterham used part number 77176 on cars with the racing brake up grade.

Brakes Int online catalogue gives MC bores.