Well there alot of good ideas and I like the Dieselpunk touches of Tannhauser board game, if the Great War was still going on in 1965 like in Iron Storm PC game the Allies sell shares on the Stockmarket to fund the war sort like a hyper version of a War Bond.
Now in this setting which I think should be late 40's to early 50's, which is perfect Dieselpunk setting. One the subject of fortfided trenches yes they would have that on the battlefield armed with Lighting gun towers, like in Gear Krieg there called Tesla Guns. Each year the Centeral and Entre powers arimes would for most of the time be in there treaches taking pot shots at each other and they would have Two to Three pushes each year and that hit run tactics as well mention previous posts.
Yes there will be Supertanks on both side would use them these great land battleships would have crew of 50 and power by four Diesel engines power plants.
Now on the homefront there would be anti German feelings and actions in North America, for example in the USA like the 9/11 aftermath they renamed foods and removed German sign and town names and removing German music and books from the public. German North Americans and British were harassed and beaten up by viglante groups.
In the USA Prohibition would still going on, due to the fact that most major breweries were own by German Americans and were seen as possable agents of Imperial Germany and most of wealthy German americans to were forced to buy war bonds to prove there national loyality.
So in this setting there would be cigerates with no filters and no chemical dips, and no American Lager.
LW