Hi there I am new to the site and trying to date a lamp I have acquired. I think it's an X246 Guardsman and I think dates from 1954 (when the Owl logo appeared ?) to 1956, (prior to October 1956 as there is no date stamp on base). It has MADE IN ENGLAND stamped on the base and has Tilley-Owl logo- stamped on the side. Does that sound correct ? thank you for any advice