Best L Duplication Prohibited Three Brass and 50 similar items

I am neither a locksmith nor a vintage arcade game person but I am like many others someone who hunts for overlooked treasure where they might find it. I turned these up and they looked official to me but I already tried them on all the local banks and no luck. Ha ha. Each on the back marked with a small "L" that appears to be from the factory, in addition two are custom stamped ("C" and "M") for quick identification. The "M" marked key is the only one that seems to have been used much and it has minor wear to the points. Something ironic that I have found to be true for even the most affluent dealers I have known, is that whatever you might make reselling something you bought from a sale or auction, you can find something thrown out and sell it for the price of two soft tacos and a drink and get more of a rush. That is about what I am asking for these so if they are of any use to you, you can't go wrong for the price.