Okay, I guess I was asleep when I took that photo yesterday. That is my Type 99. The photo here is the Type 2.
This one is not stamped. I still need to remove it and look for a proof mark though. This one does have a lot of wear, so if not original, it at least has been with the rifle for a long time.
Does look like it has some wear to it, could be an original. Here is what my proofed but unnumbered cover looks like