DP Mask Stamps

Hey guys, I couldn’t find a thread on this so I thought I’d make one to ask;
What are the stamps on each of the Shatner masks?

I believe the '75 Kirk had no stamp, correct me if I’m wrong.

I’ve never seen a 1990 until the one in the gallery, and have no clue what its stamp looks like. Any one have pics?

Now the '98 and the '99 were both stamped 1998 right? I remember hearing they weren’t happy with the 98 and didn’t want to renew the license so they stamped the 99’s “1998.”

Are there any cases of a Shatner being mis-stamped or not stamped at all?
Even DP’s The Mask. I’d like to know all about the stamps. If anyone has some info that they could tell me I’d love to hear about it and pictures are more than welcome!

~Jackson

Edit:
Something else I’d like to know about is the hair and sidebrow lines. The 99 I own has a sculpted line where the side brows go. Did any other mask have that? Also a lot of 75 Kirk replicas have a sculpted hairline. Was that present on the original '75 Kirks?