Further update on my previous post: the kayak actually dates from the late-1930's (not 1950's as previously stated), and the trailer dates from the late-60's early-70's.
I'm informed by an 'expert' , that the boat is a 'Rob Roy' type, built from a 'Streamlight' kit - but I can't confirm this as fact. The boat was built by my uncle (carpenter) with custom-built trailer built by my father (engineer). Both in good condition, unused for 40 years, hull seems sound, deck needs minor tidy, trailer will require a modern ball-hitch to be added.
Nice package - got to be worth £100 ono ? Location: Scottish Borders