Does anyone know when the serial numbers were struck on Meteors/ Mercury's If it was on final assembly/ inspection then it would seem very unlikely that a Meteor serial numbered barrel would appear on a Mercury suggesting the barrel was a later swap. However if BSA made up barrels with the numbers on them before assembly it might i suppose it just be conceivable a Meteor barrel was put on a Mercury. Reason for asking is I've recently seen a Meteor serial no. on an early Mercury & wondered if it was the original barrel.....cheers