What had never occurred to me before is that the fact of them using aventurine in 1925 may well point to paperweights having been made much earlier than previously considered.
Aaaarrrrrgggghhhhh! It's bad enough trying to work out whether folks' Ysart weights might be pre-war, particularly Salvador's work. I have still not been able to confirm (or, I suppose, deny) the idea that UV reaction can separate pre- and post-war Ysart items.
And now, the thought that use of aventurine might indicate paperweights from 1925! I can see it now ... all the Ysart-like paperweights on eBay soon being listed as c1925.

And no doubt some will insist that Paul Ysart made them, not Salvador :spls:
But on a more serious note, would it help anyone if I were to produce a photo gallery of the ranges of aventurine colour from my weights, both Salvador's and Paul's?