One thing I do on a plank build is lay the plank flat and mark two centerlines from stem to stern, top and bottom so I can inlet things lined up with barrel; buttplates, toe plates, tangs , trigger guards, and ramrod pipes. Freehanding these things never goes well.
It lookes like the return of your buttplate is cocked off to the side which would be OK if you are a lefty and you put cast off in the butt, not so for a righty.
This buttplate was a nightmare to inlet, you can see my centerlines for lay out. I put 1/4" of cast off in the butt as is visible in the layout lines.
A month later it is in, yep a month, I started with way too much extra wood for "practice", big mistake, once I started I couldn't turn back and had to remove the excess one little chip at a time, tens of thousands of them. I couldn't get the return down and and the toe of the buttplate to make contact with the wood at the same time, the toe was off the wood about .010. I heated the toe to red hot and smacked it hard with a sledge hammer, problem solved.
