Well I suppose Derik that the boat should have the paperwork from new, but quite honestly this is not a class for measuring and weighing so you don't need to be concerned.
It would be extraordinary for such a boat to have strayed from standard specifications due to the general availability of the major components being restricted to certain key suppliers (you're about to update your mainsail to an 'official' Hyde one & there are some copies out there that are not class legal FYI) & it'll soon be obvious if you've innocently bought a boat with a Sting mast & main as you line up on the start line.
I am honestly not aware in the >22 years I've been sailing this boat (on & off) of anybody surreptitiously trying to gain an advantage through the boat components.
if you speak to the Association Secretary (Andrew Berisford:
secretary@sprint15.com ) he should have the historical membership database and just maybe, you may be able to trace the hull ID & original mast ID. I think I'm right in saying that some years ago such info' was logged, but don't quote me on that just in case...
Like I say, no need to be overly concerned about the paperwork. Just tighten your tramp until the fittings bend, ensure your rudders are straight and parallel (rear of the boat in the air & drop the rudders down - check with tape measure fore/aft blade edges), fit a decent sail & battens and away you go!