There's a commercial vehicle breakers on Thorpe lane Middleton, s. Leeds.
I bought a few lengths off them out of an artic trailer for not a lot of money a few years ago.
I mounted it on my car trailer as tie downs.
Think I paid about a fiver for 4x 8ft lengths.
No connection to me, other than I needed some shoring poles and straps in a rush one day around 16:00 and they had them to me the next day. Only order I ever placed with them, but good first impression.
I stumbled upon Nationwide Trailer Parts while looking for sensible prices Anderson connectors. They do good stuff at good prices and delivery time seem very good going by the reviews.
Only thing not shown on the restraint track is the load rating but it does look a bargain.