We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember JimK
saying something like:

strung a 2mm diameter wire rope between two trees from which to
suspend assorted feeders etc...

However said rope is not level so anything hung on it will slide so I
need some way to anchor the feeders, preferably by creating "stops"
past which they can't slide??

I'm sure I've seen some kind of small "C" section clamps that I could
just slip sideways onto the wire rope and secure by tightening a small
bolt/grub screw - but I can't remember where I saw them or what the
rest of the world would use them for to start to look! -

Go into your nearest farmers' store and find wire rope clamps - dead
cheap for the small size you need.