Den, I tried the top sites thrown up by the searches you suggested, but found no new stuff there; certainly nothing to support your assertion that voter intimidation was ever an issue.
This is worrying because I have read widely on the period of transition from armalite to ballot box and the winning of the Nationalist vote, and also never saw any reports of that as an issue.
Also, I have discussed this same topic here before many times with the likes of Divis, Ard, The Curator, and indeed yourself, and it has never been raised before.
It is as if you just made it up in order to deny an uncomfortable fact, i.e. that there was little Nationalist support for the IRA terror campaign.
Please give a credible source