I am wrestling with this one.
Before we open it, should we now update it with the latest versions of the claim?
For example, you cite The Guardian on Sep 22, 2014, but by 2017 the discussion has moved on:
An expert in Russian cyber-operations has accused Russian activists of running a disinformation campaign to discredit the Scottish independence referendum result, by wrongly alleging it was rigged.
The Electoral Commission, the UK authority that oversees elections and referendums, ruled the event was fair and could find no evidence of fraud in any counts, and nor did the police.
I don't endorse this expert's speculations. I am just showing that readers of The Guardian may well have changed their understanding since 2014.
Maybe I am getting off track here. Taking it back to first principles, rather than rely on a 2014 article for notability, we should be sure there is still a widely-believed claim.
The same 2017 article states:
Its voter research did, however, uncover evidence that Scottish voters were more suspicious of this event than previously seen in the UK. It said 42% of yes voters thought fraud took place, compared with 21% of no voters.
So, I am comfortably there is a widely believed claim, but would you like to put some more up-to-date examples in the question before we re-open?