I believe the forend iron and the long wood screw played a significant part in the split.  The screw diameter is tapered a good bit and the top of the hole was certainly too small.  Minor diameter of the screw grows from .114 to .125 and then .165 past the treads.  I opened up the hole to a depth a little past the end of the screw and then bored the hole to .175 at the entrance to clear the larger diameter under the head.  Then I clamped the forend snuggly and worked the screw in to reform the threads, added a little wax for lube.  The forend iron would no longer fit in the groove.  I had to remove a fair amount of wood so that it would fit.  Maybe .010 or so.  Lot of shrinkage over 113 years I guess.
![[Linked Image from i.imgur.com]](https://i.imgur.com/q1FHgJ7.jpeg)