Seems jjc went belly up around 2007/2008!
Common alternative in Northern America seems to be Model Sounds INC in Ottawa Canada.
Not exactly cheap, but pretty comprehensive👍
They were (in 2008) going to use Action R/C Electronics as UK distributor, but that idea died, for known reasons, before it got going.
They were originally called Model Solutions of Canada Ltd, until 2011.
If you now search for ModelSolutions.ca you'll end up on an Online Casino page in California🤔
Cheers, Doug 😎