I think your listing description is ok, based on the known facts to date and, as you rightly point out, as shown in Bob Hall's book Scottish Paperweights
It is true that several of the canes in items such as your bottle will have matches in Richard More's excellent site for Stathearn weights. I have an example of a weight and a bottle that show similar features. The bottle and some discussion is shown in my pages at:http://www.btinternet.com/~kevh.glass/pages/Inkwells/Inkwells.htm
(click on the bottle centre back in the first image for details)
I have made some attempts to research examples of these items, all of which contain a mix of "later Strathearn" and early Vasart canes. Some sources say they are Strathearn and others have suggested they are by Jack Allan (which would suggest either late Vasart or Strathearm but only up to 1968, or Perthshire Paperweights 69 to 73, or perhaps even the few years he was at Caithness Glass).
However, my UV checks of both bottles and weights show that the glass batch reacts like "modern Scottish" work (including some from Perthsihire Paperweights of around the mid to late 70s and later). The reaction does not tie in with any Strathearn pieces I have tested and that includes signed and dated items up to 1979. I do still need to check the UV reaction for confirmed late experimental Strathearn pieces.
However, if they really are experimental Strathearn (79 / 80) then the UV reaction indicates that, for some items at least, they were using a non-lead glass as well as the regular lead-based mix. During my investigations I have spoken with both Herbert Dreier and Dave Moir and neither could confirm any changes of glass mix. But that cannot be taken as absolute proof that changes were not made as memories are not always clear. After all, if people asked me what was happening in my own line of work 25 to 35 years ago, I would struggle on many details.
Another source told me of a dealer who knew another dealer who claimed that items such as these were made by a Scottish worker who (I think it was said) had worked at either Perthshire Paperweights or Strathearn. The details here are a bit fuzzy and I never got very far in following up the lead.
Most of these weights and botlles seemed to appear in the market fairly recently. Bob's selection shown in his book, some of which I have seen for myself, are consistent with others which also appear to be relatively recent acquisitions.
As yet, I don't know of a verifiable attribution for these items. I am keeping an open mind on all aspects.
Would the person who emailed you with the information be willing to say whether, apart from similar canes in known Strathearn items, there is any other indication for an "experimental Strathearn" attribution?
Regarding your two other bottles, if you would like to post images via this forum, I would happy to give my comments, for what they are worth. It is known that some bottles, with a UV reaction matching regular Strathearn items, were produced with Vasart canes but with a clear neck and well section. These could be either late Vasart or Strathearn.