Ok, thank you Paul for looking through, I really appreciate it

I'll up load one more pic in a mo but here are some observations:
I've photographed the 'rim' of the top close up and there are signs of wear on it under close magnification (not possible to see with just casual looking , so it's not obvious wear) - the photo shows one part of the rim but the wear seen on it is around the whole rim.
There are no really obvious signs of significant wear
inside the piece, but the base wear right round the edge of the rim of the foot is very signficant, in that it has ground through to a completely matt ring.
So here are some thoughts:
It is possible of course that somone has stood a plate on it, or similar, in storage and hence the wear to the top rim - and of course owners stories could mean anything, but the owner told me her father (old) had said it had sat in his mother's cabinet all his life and that he believed it was an old piece. Obviously as I say owner's stories can be misleading, but to be honest I believe him. Obviously that doesn't indicate how old I know that.
So let's say I believe him, and it's sat in his mother's display cabinet for many, many years.
Added to which there are no very obvious signs of internal wear on it.
How does it then have such a matt ring of wear on the base?
It's a large and fairly heavy piece but not massively heavy.
So perhaps it's possible that it's either older than late 19th early 20thc?
or that it did have something sitting atop it, balanced in the pan top, not touching any of the interior of the pan top but which was sufficiently heavy enough to grind against the top rim and also made the whole piece heavy enough to cause such a great degree of wear to the foot - possibly a lid?
m