I just found out it's the fifth-oldest annual tournament that has never formally ended. The others are the FA Cup, the Scottish Cup, the East of Scotland Shield (formerly Edinburgh Shield), and the Sheffield & Hallamshire Senior Cup.
It's been running since 1879. It is a dreadful shame to let it fall into abeyance for no good reason. I'd like to see Morton take the lead in reviving it, even if the SPFL sides who take part do so using youth teams.