Gentlemen,
Thank you for your advice, but I think I have mis-spoken. What is at issue is the size of the "female end" of my bayonet, not the ring. It is smaller than a normal "male end" of an SMLE ( found on the underside of the nose cap, rather than the end) will fit into. I have taken a comparison picture and added it to my photobucket. The Hookie is on the left and a normal 1915 made 1907 is on the right.
Again thank you so much for your help...I really hope to get to the bottom of this one.