Sadly, I only learned about Hamish post mortem. He died within a month after I arrived in Edinburgh as a student for the first time in the autumn of 1995. He was as many a Scottish folk singer seduced and abuced by the grape, and his unhealthy lifstyle finaly and sadly caught up with him.
He was an outstanding singer and performer, as I learned by his tapes and from all his friends in the Edinburgh folk community. My favorite song by Hamish is his vesion of "Sonny's Dream", which he partially rewrote after hearing it on a Canadian folk festival. He introduced this (Newfoundland) song in Europe, and Christy Moore/Mary Black/Jean Readpath based their versions on his.
Although Hamish probably is best known for his comedy songs (It's better in the dark/Cod Liver oil and the Orange Juice/The Smoke Song), he also gave supreme versions of Irish songs (e.g The Foggy Dew) and was at one time invited to join "the Dubliners".
As for records I'd recomend "Hamish Imlach - The Definitive Transatlantic Collection"