Is this any good? Not exactly the same but it might do the job.
The light grey section is EPDM closed-cell foam and the black hatched U-shaped section is steel reinforced rubber. Bending it around tight corners might be a bit of an issue but I think the steel reinforcement is a mesh rather than solid section.
The manufacturer is a company called C O H Baines Ltd in Tunbridge Wells, Kent.
Web address is:
https://www.coh-baines.co.uk/product...-excluder.html
I've bought quite a bit of stuff from them over the years for the bus and the Amazon.