Uncertainty surrounding composer's death & copyright

[Amelia.pd]

I know that music by composers who died prior to 1955 is in the Public Domain in Australia if it was also published before that year.
I want to upload a piece published earlier than 1955 by a composer who went missing in 1944 and was presumed dead. Glenn Miller left on a plane to fly over the English Channel and the plane and its' passengers were never found.
Is it safe to upload his music, if you are unsure can you suggest where I might find the answer to this question?

I'd be grateful for any opinion on this

[Carolus]

Works of Glenn Miller first published more than 50 years ago are free in Canada, those before 1955 in Australia, with nearly everything being free in China, Japan and other 50pma countries. The problem we have here at IMSLP is due to our proximity to the USA (where most of the traffic comes from). All of his works were first published after 1922, and the likelihood is very high that they were a) published with a proper copyright notice; and b) duly renewed after 28 years. This translates into the works being still protected in the USA and thus falling into the infamous [TB] category - meaning they are temporarily blocked (until further notice). Time/Warner (or whichever mega-corporation owns the copyrights now) literally has skyscrapers full of lawyers who could be turned loose upon this humble enterprise like the legions of flying monkeys portrayed in the move The Wizard of Oz - an experience we very much wish to avoid.

[steltz]

legions of flying monkeys portrayed in the move The Wizard of Oz

Another image that comes to mind is the hordes of Orcs in Lord of the Rings.