There's a typo on the middle panel above; instead of specifying a geographical area on the second line, as would be consistent, the text reads "Bears, Wolves and Dolphins" on both of the top two lines. Just as well I pointed that out, eh? Or where would we be.
You'll notice there's no serial number on these first four sheets. At a guess, this is because BSB supplied the artwork. Letraset probably provided them with a "PR" serial number for internal use, but of course we've no way of knowing what that might have been; the closest we can get is to observe that these sets were ©1970.