I agree that it would be cool to be able to take this map back to 1939, and have another set-up. Would caution going back any further though. Reconfiguration of some of the territories and borders would be a pretty big job, but well worth it IMO. It would be pretty cool to split up S Germany and Slav/Hung so you get Austria, Czech, Hung etc….I would also like an E Prussia please, and fix some stuff like Greece touching the Black Sea etc… Also what others posted about the Italian/German border (have the new Austria/Switz between them). Might even look at creating a French buffer territory (Lorraine?) between W Germany and France (Paris), and have Italy only border S France (not France).
The easiest way to handle all these new neutral territories are to simply give them a pro axis or pro allied stance, with standing armies silhouetted (2-3 inf) just like it is done now. Hol/Belg, Denmark, Norway were all invaded so they become pro allied and get 2-3 inf to defend. Make sure that the Germans are se-up to take them by force in a 1939 set-up. Territories like Austria, Czech, Hung, Romania, and Bulgaria become pro-axis and their standing armies are integrated into the German army (just like Bulgaria…).
You could go a couple ways for the territories that would be neutral in 1939, but fully integrated into a major power for the primary 1940 set-up as far as color scheme.
I agree it would be ok to shade them towards the power they will be integrated into for the 1940 set-up (sphere of influence). This would make it easier to set-up 1940, and count the income. Could have a darker color for territories of the main powers showing their 1939 stance, and have a lighter shade of that color for the territories that will be in that powers camp for a 1940 start date or shortly after (either by annex, or by force). Like Germany, W Germany, and S Germany are dark gray, but Hol/Belg, Denmark, Norway, Finland, Poland, Yugo, Slav/Hung, Romania, Bulgaria are a lighter shade of gray. Russian territories are a dark maroon, and Bessarabia, E Poland, and Baltic States are a lighter shade distinctive to Russia……maybe even make Vyborg, and NW Persia shaded to Russia. The only problem with that is it does make it per-determined and cuts Italy out of the neutrals other then Albania, but with a 1939 start date they would also be neutral, and would the Germans really allow them to gain Romania or Bulgaria?
If you use one color for all neutrals I would still keep the diagonal lines that depict pro axis, pro allied, and straight lines to show true neutrals but probably make them a little darker (would keep the lines for either theme). Using nation specific roundels for each of these neutrals would be cool for house rules that link the parent country to their colonies, but it could also clutter the map. You could even boost the standing armies for the true neutrals to allow them to be invaded breaking the true neutral band of brothers thing we have now.
One other thing, if you are going to change some of the IPC values I would probably do a re-set for the Russians. Make Moscow worth more (3 IPCs really?) and some of the far east 0 IPCs so the Japanese don’t get much value. I think you can consider a 2 IPC territory out east, but I would be careful not to make it a target for Japan to take or build an IC. I would also make some of the oil rich territories worth more and remove some of the NO’s for taking them. Maybe boost Romania, Caucasus and the Mid East territories (why would Persia be more valuable to Germany or Italy then for the UK?). Same with the DEI, both sides would benefit from the oil (Celb had no oil and should be lower according to Imp Leader). You could make an NO for holding a region w/resources showing that you can actually ship the resources (convoy routes, or links back to an IC).