It is possible that the stock on this gun had a crack on at the head. Cracks on the centreline of the stock at the head end are some times repaired by gluing and fitting a bolt sideways through the stock to act as a clamp in order to prevent extension of the crack. I have seen many such repairs, some times the bolts are engraved to match the action of the gun. In this case it is possible that the pearl inserts have been used to cover the bolt.
Guns by K.D.Radcliffe were made by the Birmingham firm of Wrights,their work was of the very highest standard, infact they made most of Churchills box locks in the 1970,s, if these people also made Leech,s guns it will be truly of best quality.