I completely agree. The rifle is a "mix-master". Nothing wrong with that. That's what kept them in the game.
The early bolts, like you have, are generally not considered safe for shooting. It might not headspace correctly, never know. A nickel steel bolt would go great with that rifle, but they can be pricey. A3 bolts are cheap, but personally, I would try to find a bolt with the swept look of the later SA bolts. Lots to choose from.
Besides the bolt, I would not change the rifle.