OK, here’s the answer:-
The customer of mine who owns the bits originally rescued them from an old watermill. If you bolt them all together they make a spiral chute that was used to take the flour sacks from the filling station to the loading bay. Of course they would have been nice and shiny in those days, and the idea of the spiral was to save space and prevent the sacks from gaining too much momentum before they reached the bottom.
I suppose you could always make them into a suit of armour to escape the taxman but the thought never occurred to me; I may mention it to my customer who owns them!
I’m running out of strange things to test your knowledge with, how about some other member having a go at posting a mystery object?