Rob,
Fantastic, as usual!
As a note, the Soviets might not nuke the SAGE-linked sites. My dad installed the SAGE system at that time (the Pinetree and Mid-Canada line) and was present for the Skyshield exercises. NORAD radars were completely ineffective due to ECM. It's an open question if the Soviets knew this as well but it's possible why they probably would come to the same conclusion on their own, they may just decide to neutralise the radar sites to be sure.
http://en.wikipedia.org/wiki/Operation_Skyshield
There is an alternative version of the same events, not as succinct as yours:
http://www.alternatehistory.com/disc...ad.php?t=65071
Not as useful for TMP but interesting is the alternative history novel
Resurrection Day. Set in 1973 ten years after a nuclear war sparked by the Cuban Missile Crisis leaves the USA under a military dictatorship led by a general not unlike Curtis LeMay.
http://en.wikipedia.org/wiki/Resurrection_Day
A book on this theme that I've used for inspiration is
The World Next Door, another alternative history set decades after a nuclear war is touched off by the Cuban Crisis. Like some other books, I found the original short story was actually better than the novel.
http://en.wikipedia.org/wiki/The_World_Next_Door
Tony