6V6GT, NATIONAL UNION, MATCHED PAIR ,VT-107A, GREY GLASS, JUNE 1944 PRODUCTION, HR DATE CODED

6V6GT, BRIMAR, BLACK GLASS, BLACK BASE, GREY BASE PRINT, 1957 MANUFACTURE, CV511

6V6GT, BRIMAR, BLACK GLASS, BLACK BASE, ORANGE BASE PRINT, 1954 MANUFACTURE, CV511

6V6GT, BRIMAR, MATCHED PAIR, BLACK GLASS, BLACK BASE, WHITE BASE PRINT, CV511

6V6GT, SYLVANIA, ,VT-107A, 10CV/511, GREY GLASS, 1950S GREY ENVELOPE

6V6GT, SYLVANIA, MATCHED PAIR ,VT-107A, 10CV/511, GREY GLASS, BRITISH AIR MINISTRY 10CV/511 WITH 1950S GREY ENVELOPE SLEEVE