I've been in the grip of SERAD and have bought several razors lately. A few of them came with old blades still in the razor - yikes, wasn't expecting that the first time. Anyway, I now have some used Valet and Damaskeene blades though a couple of them are in very good shape. They don't take up much space so I'm inclined to hold on to them but what are folks thoughts on these old blades - trash or treasure?