That's a pity........although the 'M Myers & Son' has been individually hand stamped, which is a bit of a warning........mass produced items would have had the markings rolled on in all likelihood.
Does anyone know if any of the originals were marked with just a broad arrow & were devoid of a maker's mark/logo? A collector that I know in Northern France, who has a track record of turning up much high quality stuff, had a piece of rust stained knotted string with six of them threaded on it, when I met him at a show about fifteen years ago. They had an old faded looking blued appearance &, as mentioned, bore no markings whatsoever, save for a small (smaller than in Mr Clark's example) broad arrow. They were priced at a figure that made them rather expensive if repro's (not that there was a glut of repro's then), but pretty fair if originals. IIRC he gave a story that they had turned up from the collection of a very old recently deceased local collector.....but I am well aware that one buys the item not the story. I know the very fact that he had six of them might suggest they must be copies, but they looked good, & I had dealt with him before & had never seen him passing off anything I could see was fake. I bought three, one for a friend, & two to keep. If I'd been totally confident that they were genuine I'd have bought the lot. I still don't know for sure one way or the other......worth a photo for the opinions of those in the know?