Ian,
The broken link led to the same webpage as you found, the web site address was changed. Geocities.com closed down, then geocities.ws copied most of the content without asking the website owners anything?!? Anyway, the information is still online.
But other than the information posted on my website, I have no further information on these British trailers.
I do know they did not have an overrun brake (see the specs), so if yours does it is a modified one or a different trailer. Posting pictures does wonders to ID it.
Hanno