I grew up with a fantastic KTel compilation album called "Gold Rush '79 Volume 1", and this was one of the included songs. I had the album on my older sister had "Gold Rush '79 Volume 2", and both of them were on 8-Track tapes! That would tell you how far back the song goes if the name of the compilation wasn't an enormous clue.
I had a hard time tracking down this song on streaming services in recent history and there was a reason for that: Ian Matthews is also known as Iain Matthews! "Shake It" is one of many songs from his album "Stealin' Home" and the whole album is fairly great. The first four songs are especially strong in my opinion. Well worth a listen.
I have far too many irons in the fire as usual, so I recorded this in a hurry. I do wish I would have listened to the song before recording this because I might have remembered to do the bass flourishes in the bridge. Oh, well. This was the best I could do from memory. Fantastic song in my opinion.