Triceretops Skeleton Cinderella X2 But Look CTO ?

I'm sure these came from some sort of theme park or tar pits. Not sure if the lower right corner is a CTO cancel or possible part of an image that would have been formed in a block of 4.

I'm thinking a North Korean label once attached to a stamp.

I tend to agree with Doug. A lot od Communist and former Communist countries had labels attached to their stamps, centrally or otherwise.
I am just now having a big sort of my Cinderella collection and am finding many of these types of labels that long ago I placed in the 'unknown' sector !
Now they are easier to spot and will eventually have a place of their own.
North Korea for sure.

Enjoy the collection Nitro !

Londonbus1

Exactly!
North Korea 1991 (set of 5 stamps + label)
Sheet with pictorial CTO postmark