Help with wartime code please

I have been painstakingly cleaning,and nothing else. I found a couple of stamps that I cannot cross reference with anything I have on hand. On one of the bayonets I found M/158/M. On another bayonet, I found N30 and underneath that H&B. The scabbard for that bayonet has S191 stamped on the bottom. I am writing down what I have and where it originated from and these four issues have me at a complete stop for the time being. Any help on this is greatly appreciated. 

Thank you very much the Armourer.