Here are some ideas for modern civ-specific units 
Americans- No change
English- HMS Invincible or HMS Dreadnought
Indians- Sepoy (infantry)
French- Le Clerc or Mirage
Germans: No change either (maybe Leopard???)
Chinese- Red Guards (marines)
Russians- MiGs or T-34 (Hind??)
Japanese- Zero? Bicycle troops?
Egyptians: Not sure.
Zulu- Changed to South Africans
. Like it or not, they are still the most developed country in Sub-Saharan Africa. They're special unit would be the Rooivalk chopper.
As for the others, maybe we can change them to more recent civs?

Americans- No change
English- HMS Invincible or HMS Dreadnought

Indians- Sepoy (infantry)
French- Le Clerc or Mirage
Germans: No change either (maybe Leopard???)

Chinese- Red Guards (marines)
Russians- MiGs or T-34 (Hind??)
Japanese- Zero? Bicycle troops?

Egyptians: Not sure.
Zulu- Changed to South Africans

As for the others, maybe we can change them to more recent civs?