a long shot but it looks like it could go in the end of a pipe/tube then when the other end is pulled it spreads in the pipe to secure it. like you would use to lay pipe through a mole tunnel for cables or irrigation…….. like i say a long shot??? not sure where the file comes in though. it might also hold something in the centre and you tap down the brass ring to tighten it??
We have moaned about the affect of the rain on the clay ground around us in Devon, but after the floods and damage in other areas our soft ground isn’t worth a mention. Our thoughts are with those affected.
Thanks for the info, unfortunately I can’t send pm’s. Not quite got the space at the moment to work on the engine, I don’t think the Gem need worry, there’s room for both.