Claim: Green Mace or QF 127/58 SBT X1, was a 102 mm, 28,000 kg (62,000 lb) British heavy anti-aircraft gun developed by Vickers in 1956.
Evidence: Green Mace, also known as the QF 127/58 SBT X1, was a British heavy anti-aircraft gun of the 1950s. c. 1956 Vickers 28,000 kg (62,000 lb) 102mm