There's an excellent article in the MKLalong with a 138 pic photo montage of Homer's rifle.
1944 No.1 Intermediate Shortened Lightened Rifle (Mfg by SAF Lithgow)
They only made 100 of these experimental rifles ...
There's also an excellent artticle by Terry Hawker...
Shortened No. 1 Mk III* Rifle
Regards,
Doug