Can't think where else to ask so here goes.
Someone I know works in glasshouses and is looking to source more of these things. They use them to hang electrical cables, but that may not have been their original purpose.
What are they called? Do any of you recognise it? View attachment 18047
It looks a bit like something Unicol might do, but definitely isn't. For hanging tv's.
As has been said, making one would be a good project for a metalwork apprentice or an enthusiastic person who posts on Thumped.