It would appear to be a connection on an extending rod system - the wooden
poles having rotted.
We had a similar set for drain unblocking, but had brass connectors.
Is the "egg" piece hollow? is there place for a rod in the top of the
connecting piece?
If not maybe the upper part is a replaceable tip which gets damaged in use.

if solid, the "egg" part is a connector to another missing piece (I assume
a rod).


I don't think that the smaller part is hollow, I'll send your comments on to the
owner and see what he says. Thanks