Hello Peterr. I've just spent an enjoyable half hour looking though my Shetland tunebook collection for the tune in question, without luck. Then I looked at my LP sleeve and noticed the track was probably played by The Cullivoe Fiddlers. This tickled my brain and I remembered I had a CD of the Cullivoe Fiddlers. Yes - I found the track! It's called

Da Gloup Lasses
"A man named Horace Saxby came to live in Gloup in the early 1900s. He had previously been in the Canadian mounted police. One day in spring he came out to see Willie Barclay Henderson who was in the fields sowing corn. Saxby was anxious to teach him this tune, which he had composed. He couldn't play the fiddle, so he had to hum the tune over to Willie, correcting him as they went along. The tune quickly became popular with the local fiddlers."
- The Cullivoe Fiddlers (2006, Shetland Arts Trust CVOE1)

Gloup is a village in Yell.