Yes. Until 1975 the Isle of Lewis was part of the county of Ross and Cromarty. Separated from Tain, as I've already said, by the width of the whole of northern mainland Scotland plus the whole of the Minch. Since 1975 Lewis has been part of the Na h-Eileanan an Iar/The Western Isles local authority area, and Steòrnabhagh/Stornoway is the administrative centre of that area.
I see in the second document that Murdoch 'first attested' at this 'Stromway Isle'. Not that he was born there.
Stornoway/Steòrnabhagh is only one of several parishes that make up the Isle of Lewis.
Not sure it's correct that the Earl of Seaforth was from Stornoway/Steòrnabhagh. His title certainly derives from Loch Seaforth in the parish of Lochs in Lewis but the Earls of Seaforth were a branch of the Mackenzies of Kintail, on the mainland, and the Earl's seat was Brahan Castle, in (I think) the parish of Urray, near Dingwall. Dingwall was the county town of Ross and Cromarty, that is, the administrative centre of the historic county.
So there's nothing in the second document to suggest that Murdoch was born in 'Stromway', whether or not that is a misrepresentation of Stornoway/Steòrnabhagh.
