Let me tell you, this was one of the most difficult and challenging headstock repairs I have ever done. There simply was hardly any surface area available to bond the two pieces together. Making matters worse the damage was done some time ago.
I actually completed the repair multiple times to finish the job. The first repair, the two splines simply failed under pressure from the headstock. Again I think this was due to not having much surface area to bond together otherwise. The final repair included two splines on the side of the truss rod spanning nearly 8 inches. I also added a spline up the middle.
The repair left the headstock angle slightly forward - think Fender instead of Gibson. Due to this I am having to install a String Retainer to keep the strings down. I am not happy about it and quite frankly am really let down how this repair ended up for the amount of time involved. Overall I think the customer will be happy with the result and will be able to enjoy and play the instrument for years to come .
Sometimes they just don't go as planned . Major repairs are not paint by numbers and there is no one size fits all method. Anyone that tells you otherwise is full of shit. Sometimes they go really smooth and sometimes they don't