Max ...
I know how you feel
In simple terms, for the purpose of an eBay sale, I suggest a description along the lines of, "Perthshire Paperweights, design number PP1, unsigned, pre-1978."
The "PP" numbers are just design numbers for the various patterns.
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Kev's rationale for wordiness:
The recent increased interest in paperweights within the Board has begun to show that attributions can be just as tricky (UK meaning, as opposed to possible US variation) as with much of the other Art Glass.
Therefore, one of my "reasons" for all the analytical stuff is to put folk on warning that when it comes to paperweight identification, many items really do need careful consideration to justify an attribution. I also like the sound of my own typing - so lots of words makes me feel good.
Seriously though, I could have just said, "Sorry, Ray's wrong with PP5 or PP6, it's a PP1 design." But without the evidence, somebody else could then have said, "But I have a PP1 design weight and it's different". Frank's example photos of two completely different PP5 designs shows how confusing it can be.
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Leni ...
Your weight that is "very like Max's" could well be a Perthshire Paperweights PP2 design, pre-1978. But without seeing a pic, to check the canes, can we really rule out Strathearn or Vasart? Dunno.