There are different types of cross pieces in L1a3 bayonets, hex or streight. I have a 1986 made L1a4 (AM86 stamp) bayonet which seems to have a stronger blade. Probably one of the last SLR bayonets made.
Thank you for the tip on broken cross guards, this may explain why some people attempt to sell SLR bayonets as "fighting knives".

Kind regards, Lester