At 450, that Carbine was a steal, you are a lucky man. Yes the ser# is in fact in range (however as I am still learning I may be wrong, but I believe they go from 104k-130k or so), front sight is correct, saddle ring is right. Stock seems correct. Not too savvy with rear sights. Might be correct, might not. Cartouche behind the saddle ring is correct. Make sure the barrel is 22". All in all, I would say it is a carbine.

Dick Hosner, 98src, or either Mr. Butts will let you know the exacts im sure. They helped me alot identifying my Krag.

Good luck