Pfft does it even have a Mandolin crystal?
most likely, yes.
Keep in mind this is a 1386303: The very first model M. It predates even the industrial one by a few months.
I'm not sure if I recall how old killerbee's oldest model M was, but it's surely not that much older than this. I do note that they have different keycaps.
But guys, it's very rare and hard to find
It really is. 1386303's don't show up every day like 1391401's do. Especially not in this condition.