Hoeray for wikipedia as at first i had no idea what you said here
This one was probably built in the UK and exported as a unique car, so not the Exmo series.
Sliding pillar suspension, first used in 1898 , so.... is that a good thing or a not so good thing ?
( i understand double wishbones and McPherson suspensions but never heard of this one )
If you are interested in the European mainland prices,
this is the leading website for second hand (and new) cars for Belgium with quite an offering from the rest of Europe too.
Personally i use the Flemish version, but i can't get that in english, i suppose the cars listed are the same.
You can do a search on Caterham, Westfield, Lotus but not on "Robin Hood"
There is a workaround: simply do a google search for "autoscout24 robin hood"
and you should get the listings for Robin Hoods.
( check "Country" is set to Europe. )
I also found a dealer in Holland with a nice collection,
might save a bit more cash and get one of his Westfields.