According to:
http://en.wikipedia.org/wiki/List_of...A-1_Skyraiders
and
http://en.wikipedia.org/wiki/List_of...t_F4U_Corsairs
There are 14 airworthy A-1 skyraiders and 26 F4U Corsairs in tbe US. Since the Naval Aviation community is tight knit, and retired pilots remain closely tied to the active force, I'd suggest that a squadron of Skyraiders and a Squadron or two of Corsairs could be available to US Navy and USMC in T2K to support counterattacks.
Here is how it could have gone down. When the Mexican forces crossed the border, the Commander of 2nd Fleet, the Aviator Admiral Hank Jones reached out to his friend and former mentor, retired Navy Captain Tom Gracion and asked him what the Naval Avaition Association could provide. The Assocaition, consisting of Navy and Marine Corps pilots had access to a extensive collections of aircraft but no weapons. The call went out and the Association was able to scrounge together from numerous sources 10 A-1 skyraiders and 20 Corsairs. Over a period of a year, these aircraft were flown into Naval Air Station Pensacola where they were rearmed mostly with .50 cal machine guns and modernized bomb racks.
The Graybeards of the Naval Aviation Association served as trainers to help convert active pilots to the older aircraft and sometimes flew them operationally. Eventually, after many delays and a huge amount of improvisation the Navy was able to field a squadron of 10 Skyraiders (assigned to reconstituted Navy Attack Squadron (VA -2) the Beasts) and 20 Corsairs. 10 Corsairs were assigned to VA-6 (Fist of the Fleet) and 10 Assigned to Marine Attack Squadron VMA242 (the famous Black Sheep).
Though operations were extremely limited by fuel supplies the aircraft though obsolete were relatively easy to maintain and provided effective close air support.
Similarly a wide range of commercial aircraft operated (and often owned by) members of the Naval Aviaition Association were used for recon, scouting, light cargo and liaison duties.
VA