Hi Rhys
To our modern eyes the repair to the stocks wrist looks crude but when it was done some time and effort was put in to make it functional and aesthetically acceptable, also it has functioned satisfactory up to today. What I am trying to say is that repair is part and parcel of the guns character and history so just clean it up and may be oil the stock and wonder how it was broken in the first place and speculate who did the repair and why, also that repair makes the gun unique if the repair is sound and the gun fit to use it would be a fine conversation piece any way.