Look for anything with sisters Triona and Maighread Ni Dhomhniall.
They were together on the rare Skara Brae record from around 1970; Triona recorded with the Bothy Band and Relativity and later solo; and the sisters more recently have again recorded together.
Also Karen Matheson in Capercaillie. My preference is for the first 3 albums, before they added a drumkit and spoiled their sound.
I have no idea as to availability on vinyl. This isn't material about which you can afford to be too picky.
