And weigh between 5.6 and 6.1 grams - all work with a twist action. Maker "W.M.Ld" for William Manton Ltd = hallmark 1966 Birmingham - weighs 5.6 grams - straight blade. Maker "JS&Co" for J S &Co. - hallmark 1980 Birmingham - weighs 5.6 grams - straight blade.
