... the presence of the bullaun stone does hint at very strong links with Ireland, even if those are simply trading ones.
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As an observation: I can see that the Scots in these times of getting closer to independence may well wish to disprove the Irish connection and create a bit of indiginous history. I would view any conclusions reached at the present time very carefully.
This is not to say that one interpretation is better than the other obviously.
The Columba links would need to be re-evaluated too and they're pretty well recorded.
hhhmmmm ... makes you think don't it!?