Not a bad price for a now-scarce part for a TT or other vintage bike. Good seller. MikeV

https://www.ebay.com/itm/334371454719

Can anyone out there decipher the numbers stamped into housing on this master cylinder (believe these are not Brembo reference numbers!). I'm interested to know who stamped them and what relevance they have. Presumably the last 2 digits are piston size, but why 2 different sizes on this one (did it start as 14mm then rebored to 17?). For reference, my Montjuich has similar stamped numbers on each of its (standard black) Master cylinders, but only the underside - they are F/Brake = 21 KO 15 + Clutch = 10 A6 15 + R/Brake = 15 A2 12, hence my interest - Richie.