Yep the lock is worth probably 4X what you paid for the rifle. Ya did quite well ol' son.
It's a custom build from a person who is new to building long rifles..., OR from what the photo shows the person is new to building rifles from a stock blank.
The butt plate edges for the plate itself should be flush with the stock....in fact the stock from the wrist backwards has a very modern shotgun-ish appearance.
The lock mortise was done wrong as well, for if a tail is present (wood from the mortise from the back of the lock to the wrist) it shouldn't really be any longer than the diameter of a nickle and in the shape of a teardrop, and smaller would probably be even better. The shaping around the lock mortise is also a little too square. However from what I can see, the carving, though not from the time period of the embellished long rifles, seems to be rather good, the finish seems very good, (need some close-up shots of the lock) I'd guess a lot of the wood to metal fit is also quite good..., so I'd venture a guess that the builder has done gun stocks for modern guns..., just not for long rifles.
So it wouldn't win any awards at Dixon's Muzzleloader Builders Fair....,
So What! The proof in the pudding is in the eating, and the proof of a rifle is in the shooting! If she shoots straight, and is reliable, cosmetics are a secondary concern. Take a deer with her and you'll have no qualms about her appearance. I've seen several rifles that are plain butt-ugly compared to yours, and they shot well; their owners going home with meat and/or ribbons at the local shoots so not to worry. Heck for $40 I'd a bought her if she was made with plain birch and stained purple! And I'm a right handed guy!
OH and if you're a lefty and happened to come across this amazing buy..., also in left-hand..., I'd venture you were meant to have her. Yeah, folks say I'm superstitious about such things, but stuff happens for a reason.
Enjoy and send us photos of your targets when you get a chance.
LD