Hi, Welcome to JustAnswer! My name is XXXXX XXXXX I will endeavor to answer your question.
I have been running a worldwide Craigslist search and eBay search every day since you first posted the question.
Something you my be very interested in is www.CraigsPal.com which is a free automated Craigslist searcher program. It delivers filtered Craigslist results based on your specific & personal preferences and you can search the entire world! The software is minimal in size, uses virtually no memory, has no spyware or adware and SAVES YOU TIME!
The basic version is free but there is an expanded version you can buy.
It might be very helpful to you in your search.
Here is the name and contact # XXXXX Mr XXXXX XXXXX On 07939 928551
He was one of the guys who made the speakers at Brinkman. It might be possible that he would knw where there is a pair for sale...?
Also here is a number for a guy in London who had a pair for sale over a year ago.