WW2 British No.4 Mk.I bayonet

The No. 4 Mk. I was beautifully made, with its distinctive cruciform blade. The bayonet and socket were one solid forging.
Only 75,000 of this type were made. Production occurred during the latter half of 1941 and into the early months of 1942. The only maker was the Singer Manufacturing Co. (the famous sewing machine people), at their Clydebank, Scotland plant. One influence in the selection of Singer was that Scotland was felt to be safer from German bombers than England.    

Information regarding this bayonet was found at this website. http://worldbayonets.com/Bayonet_Identification_Guide/Britian__No__4_Spike_Bayonet_/britain_spikes_2.html