Not the Lunnys, I think. There is a much stronger connection between Scots and Irish Gaelic through the singing of Triona and Michael O'Dhomnaill, who I think are fluent in both forms of the language. Before the days of "The Bothy Band",Michael recorded an LP with Daithi Sproule as "Celtic Folkweave" - quite hard to come by these days - and I'm sure there were 1 or 2 Scots Gaelic songs on that.
One other instance, from only last year I think, was the singer Brian O'hEadhra, formerly of the group "Anam" who has been living in or around Inverness, who had recently written his first song in Scots Gaelic as opposed to Irish. A fine piece of work it was too.
Although Manus Lunny sings and writes in Irish Gaelic, I'm not sure that he's ever done either on Scots Gaelic, apart from the odd chorus with "Capercaillie".