Mythical Dragons

I have just accidentally found a particularly unusual propelling pencil that was made for/by Wyvern in the 1940's. It's very desirable for me and something that I want to add to my collection. I then go and stumble on four more identical writing instruments over the next two days. It's sort of London Buses isn't it? None for ages and then a load turn up. My chances of owning one? Probably the same as my chances of winning the Euro Lottery.