Broadback wrote:
Having Googled for this they all seem to be USA. I'm fed up repeatedly
getting punctures in my wheelbarrow tyre. Any suggestions as to how or
where I may obtain a solution to this?

I don't like using barrows with solid tyres at all, it's
hard work. Perhaps a new tyre would help, or you could
put in some "Finilec" or similar "puncture proofer".