That is a decent price, but if concerned about originality, make sure it hasn't been reblued. Most Type 99's have serviceable finishes, but not what most folks would call "beautiful."
Yes, this came to mind as well, when I read the post. Of the Mums that I have seen, all were stamped fairly deep. Taking this post at face value, I'd say this was a very good deal. The mud cover is fairly common but you don't see many mono-pods. ....
Be Safe !!!