I remember Bob Scafe making a comment years ago that when given the chance a collector should bring everything back to examine more closely as time allowed. This is what he was talking about. Last week I had the chance to pick a few from a 500 Kv line rebuild dumpster. I got these four of what I thought were all OB with the 1918 pat. date caps. I was much surprised to find one was an ink stamp CP. And no, it's not the copper coloured one as you might expect.