Before I start, I have no idea if anyone has done/proposed something like this before, so if they have I do apologize - I did not find anything through the searches, so if this is the case then please let me know as I'd love to see an actual implementation!
The idea is something I plan to eventually implement into the full campaign HDM scenarios when I eventually get around to making them. In the meantime, if anyone wishes to use anything here - please feel free, part of why I posted this is just that.
So, with all that out of the way, what is the idea?
Basically, it is an attempt to counteract the lack of flexibility the allies face in terms of production, by using the one 'currency' they do have - Political Points. This represents the ability for the militarily leadership to exert some pull to get more airframes, reserves released, etc. This is similar to the way these points are used to free up LCUs from the West Coast, change leaders, etc. and so is in my opinion a rather elegant solution.
How is this done? The easiest way to demonstrate is this completely impromptu mockup I made based on Scenario 1.

The first part is the addition of 5 bases into the off-map section of the West Coast. These are completely isolated, and therefore the LCU's and airgroups based there cannot be moved anywhere. There is one base for the USAAF, one for the USN/USMC (since they use mostly the same airframes), one for the British, one for the rest of the Commonwealth, and one for the other 'minor' (airforce wise) nations, such as China, the Netherlands, and French forces in the Pacific.

There bases are distinctively titled, with their names surrounded by round brackets. This means they are easy to find at the top of the bases list. Here we will look at the USAAF base (I only filled out a few of them).

This is a list of units at this base at the moment. As the game continues, more units would arrive with newer airframes for 'purchase'. Typically they would fall into 3 groups, in order of increasing cost - 'reserves' which represent aircraft pulled out of mothball or training groups as a stopgap, 'extras' representing more of an airframe already in production, and 'diverts' representing aircraft diverted from the ETO that may not be in production at the time or at all (P-40F?). The /1, /2, etc. represent repeats of a group, and these will typically get progressively more expensive (acquiring 20 more P-40s might not be that hard, but by the time you're asking for the 60th...). Here I will look at the P-36A Reserve group.

The thing to note here that it is an entirely regular airgroup, statically restricted. It could also be used for training, though this should be subject to HR's as this could potentially give the Allied player a MASSIVE on-map training program. The groups will also come with pilots, so in addition the the airframes you get an injection of pilots of varying quality.
The thing to note is that the commander is a CPT 120PP Release ('he' had to have a rank..). This is the trick to how this works. These are commanders given PP change values representing the value of the squadron (capped at 255 sadly).

To 'purchase' the squadron, the Allied player changes the commander to an existing one. Here he is being replaced by Colonel P.E. Tron, for 127 points. The '120PP Release' commander is actually set to arrive in '47, and so will not show up even in other airgroups or divided units as a result of 'random' commander assignment. He is effectively gone for the rest of the game.

After this is done, the Allied player 'disbands' the airgroup, releasing the pilots, airframes AND the newly assigned commander (Colonel Tron) to the pool. As there is no point to rebuilding these squadrons, the player should choose 'no' when asked the 'rebuild in 120 days' prompt to avoid clutter.

The end result? 24 new P-36A's ready for deployment! A reserve group like this is a cheap way to acquire airframes to fill out west coast / on-map training groups to free up the better airframes for combat, whereas the more expensive 'extra' and 'divert' squadrons are typically front-line aircraft anyway.
Obviously, this entire process is reliant on the players trusting each other not to just 'disband' the squadrons without paying the costs, though of course the option to do so actually opens up some nice HR options, such as allowing this to be done to a certain number of groups if somewhere important like Hawaii or Australia is invaded. I don't see the trust issue as a problem as it is really no different to many HR's such as the 'PPs to cross borders' one.
There are a few other issues I forsee, such as the ever increasing amount of airgroups cluttering the airfield (I can't set them to withdraw otherwise the disband does not work as desired), and the fact that since the 'price' will be fixed throughout the game, a 1944 frontline 'extra' squadron will be just as expensive as an at that point obsolete 1942 'extra' frontline squadron. Then again, I suppose most of the 'extras' will be in '42 and '43, while the later war years will feature more 'diverts', such as getting P-51s or B-17s in theatre sooner/as needed.
It would also be really nice to be able to stand the squadrons down properly - setting them to 'train' and 0% in the editor defaults to 30% training, instead of stood down. 1% training is the best compromise I could find.
Thoughts and comments very welcome!
Juan