Patrick (in the UK) ..if you haven't seen a Thames in wood on your side of the pond, then perhaps you are correct, maybe they never made one.
Although, I thought I recalled seeing a full size woody Thames project in restoration in a magazine....but don't know if it was for real - or a project someone dreamed up.
My searches online haven't turned up much, so I think I'll just wing it, and have some fun fun fun.
Since they like surfing in Australia...maybe this will be a concept for a surf buggy "down under", as they say.