Australian 1944s Shilling Struck on Foreign Planchet

mnemtsas2

I've been sitting on an Australian shilling struck in San Francisco in 1944 for a while. It's struck on under sized 4.94g planchet which I thought was a war nickel. The coin has just come back from PCGS where they tested it with their XRF machine and it came back with this composition:

55%Ag 42%Cu 2.8%Mn 4.94g

Any ideas what sort of blank this might have been struck on? It's obviously not a war nickel.

Here's the PCGS images:

DorkGirl

The only help I can offer is a list of all the foreign coins struck in the US. You will need to look at 1944 issues.

minterrornews