Question about number on Arisaka bolt/extractor

Just noticed something strange about my Type 99. I've noticed that typically a T99 will have serial/production number on the bolt stem and the rear of the extractor. The number on my extractor is on the other side, where the claw is...stamped on the side of it. So if you were looking at action from above and you unlock the bolt and slowly pull it out, the serial number is stamped on the side of the claw facing up. What's up with this? Is my bolt off a different type of Arisaka? I tried searching and couldn't find references. The extractor number does match the bolt. However, the safety knob appears to be from a type 38 (it has a protrusion instead of a notch) but the number does not match the bolt. None of the numbers match the rifle itself. It looks like a 99 bolt, but then again they all kind of look the same. Anyone seen this before?