Historic MGB ?

[grumpy52]

Any knowledgeable bods of early MGBs.
Trying to find some history of a car that is supposed to be one of the first with a 5 bearing engine and used at Le Mans .

[grumpy52]

We are trying to find some definitive history of the early years of the car .
The current owner has the later history but the early history is a bit vague .
Like many used in competition things have been swapped or replaced over the years .
Manufactured in Jan 63 but not registered until August of the same year . It did spend time with the Competition department at Abingdon.
Any help would be appreciated