This World War Two Australian made battle dress uniform jacket belonged to a member of the 11th Marine Regiment, 1st Marine Division who participated in the battles on Guadalcanal, New Britain, and Peleliu. These Aussie made jackets were very popular with members of the First Marine Division early in the war, because they were not able to obtain US made dress uniforms.
This jacket also has a theater made First Marine Division patch sewn on the right arm. Although the US Marines normally only wore divisional patches on the left arm during WW2, period photos of these Australian made jackets being worn by members of the First Marine Division, often show the divisional patch being worn instead on the right arm. Also, many of the surviving Aussie made First Marine Division jackets that I have examined have the patch on the right arm.
I own several of these Australian made jackets in documented groups and only one has the First Marine Division patch on the left arm, the others all have the patch on the right arm. Interestingly, all of these groups have other patched uniform items that are later issue and are US made. On all of the other later issue uniform items in these groups, the First Marine Division patch is on the left arm. Period photos also reflect this trend of the divisional patch migrating from the right arm to the more conventional left arm as the members of the First Marine Division transitioned from wearing the Australian made battle dress to the US made USMC uniform.
This particular uniform also exhibits two other common traits seen on these Aussie made uniforms when worn by members of the First Marine Division. First, although theater made EGAs (Eagle, Globe, and Anchor insignia) existed, they were often worn without EGAs. Second, these theater made jackets normally also have theater made First Marine Division patches on them.