"pair of Stilsons" = big-assed pipe wrench. Stilson company forged a lot of them and the name is prominent on the bigger sizes. I picked up the term from old folks and still refer to a big pipe wrench as a Stilson though I - and they - never set foot on Blighty. ("pair" probably refers to the two jaws that usually seem to live independent lives)
I'd like to see a pic of the remnants of that BB.
No problem, here it is - together with the Big A**ed Pipe Wrench (Stilsons)! The angle grinder might have been an extreme approach but it did make deep enough cuts to hold the tip of a cold chisel.....