If you are a fan of WW2 gear, you might be interested in the WW2 German Rucksack used by the Mountain Hunters unit featured by High Speed History. There are replicas that are made of olive canvas, natural leather, and grey steel fittings, just like the original ones.
Another round of putting together loadouts and uniforms from unlikely sources. Country Tactical puts together a World War 2 US Bomber uniform all sourced from Walmart... "Me and Mav Tried to make A WW2 US Bomber Uniform from Walmart for under $100. Turned out different from our expectations so stay tuned! This 'Uniform' cannot be used for official reenactments, however it can be used for airsoft, school presentations, and Halloween."
Is it possible to have World War II-themed Milsim game? It is possible as long as all players get the proper World War II gear which can be found at militaria sites and reenactors' groups though it will take some time. Here is Jonathan talk about it and other topics in another Airsoftology Q&A Mondays...