The Viper of Saigon is Nguyen Xuan Trang, a (former) Major General in the Republic of Vietnam Armed Forces. Here's the website where I found his image[daubinhlua.blogspot.com] and this is his wiki page in Vietnamese. [vi.wikipedia.org]

Basically all of the resistance leaders are inspired by officers from their countries, an example is The Ghost of Cairo wich is an officer from the Egyptian Armed Forces.

Pretty much what ppperetti said, I was looking for faces that looked plausible and would not be easily recognized. The exceptions of course being Immortal Father and Mother Russia -Mao Zedong and Valentina Tereshkova. I didn't want Mao Zedong at first because he's an historical figure but I felt it was plausible in the setting for the death worshippers to use his image as an immortal figurehead. And then Valentina Tereshkova was chosen because I thought "Mother Russia" was a good name for the Eurasia leader that kept with the theme, and Valentina herself looks like a very tough and competent leader but also you could easily picture her raising a large family - she just had the perfect look for Mother Russia.

It won't let me play the mod and just says "Disable a few mods" when only the 1984 mod is enabled.