Yesterday at a flea market, I picked up a 66 Super Speed. The guy asked me if I wanted some blades and I said sure. He went and dug around in a box in his booth and came back with these. They say Super Stainless Double Edge Blades, then on the container itself, says Super Silver. The package also says Made In England and apparently 5 blades sold for $0.89. I've been trying to decide whether or not to open them and try one. Anyone know anything about them?