1, never used one myself but I have a few from my grandad. I ground them to a chisel and use them for raking out mortar. Must have been a hard job - guess thats why you see so many pipes bracketed to existing timber rather than walls where they can.
2, Is it some kind of tool for expanding the ends of pipes?
3, Moleskin (I have my grandads one here somewhere. Last used it when I was 13 and my grandad showed me!)