Examples of cassette adoption outwith the sphere of Scottish traditional music.
Evangelical sermons from Scotland:
http://tapesfromscotland.org/
Various collections held by Scottish Music Centre, including several personal archives and demo tapes submitted to Radio Scotland:
http://www.scottishmusiccentre.com/collection/about-the-collection/
DIY commercial releases. Note references to Dundee:
https://recordcollectormag.com/articles/home-taping-thrilling-music
Scotsoun, collectors and publishers of audio material relating to Scottish culture, published commercially on cassette:
https://en.wikipedia.org/wiki/Scotsoun