I've seen pics of Eric's carbine that Eugene did, and it's just slightly short of beautiful!!!

I grabbed a couple of his carbine pics.
Now, for the questions...What is the difference between these two...
I can see that one has a barrel mounted 4-position carbine rear sight, and the other has a 2-position (?) toggle mounted rear sight...
Did Eugene really use a Navy to make a carbine??? Or is that a toggle he made himself???
Are the shoulder stocks all the same???
They both have 16"+ barrels...Are they legally classed as rifles???
Maybe you could take pics at every major milestone!!!