Hello fish, I commented on your earlier post. With the new pics, I can say with some certainty that the barrel has NOT been cut on your gun and you have a genuine carbine. The little "hump" that the front sight sets in is forged on the barrel. A rifle gun that had been cut would not have the hump, and would have to have some type of ramp front sight screwed on. The length difference you infer to (18" v. 18-1/2) is likely a measuring error. The barrel length will be measured from the bolt face. Your're likely not measuring to the right point.
I cannot say about the stock. My "blue book" makes reference to carbines having a "straight grip" (as opposed to a pistol grip) stock. The pistol grip cap does not look right either. Note that the grip area on Model 14 is notoriously fraglile. A portion of the bolt/hammer mechanism runs back into top portion of the pistol grip, the grip is basically a bit hollow there. Many model 14's will display a crack at the pistol grip. Yours may have done so and was replaced with a standard butt stock. It may also have been ordered that way. The grip cap.? Well, maybe home gunsmithing. The whole butt stock could be handmade job too.
The sights on your barrel are not factory. The little notch beneath the existing rear sight was a bearing surface for a screw that served as the elevator for a distinctive numbered wheel used to adjust elevation on the Model 14's. The rounded front is not factory either. The front sight on 14's was a beaded blade, set very low, and the rear sight is a low blade with the odd numbered wheel as described. Non factory sights on a model 14 are not uncommon. Mine (in .30 Rem) does not have the correct sights either. There was a guy in TX who specialized in vintage iron sights. Right now I cannot recall his name. He advertised in Shotgun News.
I would not be in a big hurry to refinish or alter the gun. Its age is what makes it special. Good luck with ammo and your hunts.
Oh yeah, the little flange on the mag tube is a brush guard.
Did this old pump come out of PA?????