Hi,
It's been forever since I've played that scenario but am I recalling it right that it's one of the ones (like Mars or Dinosaurs) where you basically start off with a settler-type unit and go from there? If so, it's basically a modpack and you would do exactly what you said here:
I know I can make a copy of the Civ 2 folder, then replace things with their scenario parts (like units, etc.).
The reason you may see "Vikings or whatever" listed as a civ is probably because the author didn't change all of the civs, and only the first 7 in the rules text. All you'd need to do is copy the first 7 lines over the next 7 lines, and then once more (so you have three sets. For example, here is this technique in "Cold War." Notice how everything repeats? That's what you want.
@leaders
Joseph Stalin, Joseph Stalin, 0, 1, 0, Soviets, Soviet, -1, 1, -1, 1, Premier, Premier
Ho Chi Minh, Ho Chi Minh, 0, 2, 1, Pro-East, Pro-Eastern, 1, 1, -1, 1, President, President
Mao Zedong, Mao Zedong, 0, 3, 2, Chinese, Chinese, -1, 1, 1, 1, Chairman, Chairman
Harry Truman, Harry Truman, 0, 4, 3, Americans, American, -1, -1, -1, 1, President, President
Mackenzie King, Mackenzie King, 0, 5, 1, Pro-West, Pro-Western, 1, 1, -1, 1, Prime Minister, Prime Minster
Clement Attlee, Clement Attlee, 0, 6, 3, Europeans, European, -1, 1, 1, 1, Prime Minister, Prime Minister
Jawaharlal Nehru, Jawaharlal Nehru, 0, 7, 2, Non-Aligned, Non-Aligned, -1, -1, 1, 1, Prime Minister, Prime Minister
Joseph Stalin, Joseph Stalin, 0, 1, 0, Soviets, Soviet, -1, 1, -1, 1, Premier, Premier
Ho Chi Minh, Ho Chi Minh, 0, 2, 1, Pro-East, Pro-Eastern, 1, 1, -1, 1, President, President
Mao Zedong, Mao Zedong, 0, 3, 2, Chinese, Chinese, -1, 1, 1, 1, Chairman, Chairman
Harry Truman, Harry Truman, 0, 4, 3, Americans, American, -1, -1, -1, 1, President, President
Mackenzie King, Mackenzie King, 0, 5, 1, Pro-West, Pro-Western, 1, 1, -1, 1, Prime Minister, Prime Minster
Clement Attlee, Clement Attlee, 0, 6, 3, Europeans, European, -1, 1, 1, 1, Prime Minister, Prime Minister
Jawaharlal Nehru, Jawaharlal Nehru, 0, 7, 2, Non-Aligned, Non-Aligned, -1, -1, 1, 1, Prime Minister, Prime Minister
Joseph Stalin, Joseph Stalin, 0, 1, 0, Soviets, Soviet, -1, 1, -1, 1, Premier, Premier
Ho Chi Minh, Ho Chi Minh, 0, 2, 1, Pro-East, Pro-Eastern, 1, 1, -1, 1, President, President
Mao Zedong, Mao Zedong, 0, 3, 2, Chinese, Chinese, -1, 1, 1, 1, Chairman, Chairman
Harry Truman, Harry Truman, 0, 4, 3, Americans, American, -1, -1, -1, 1, President, President
Mackenzie King, Mackenzie King, 0, 5, 1, Pro-West, Pro-Western, 1, 1, -1, 1, Prime Minister, Prime Minster
Clement Attlee, Clement Attlee, 0, 6, 3, Europeans, European, -1, 1, 1, 1, Prime Minister, Prime Minister
Jawaharlal Nehru, Jawaharlal Nehru, 0, 7, 2, Non-Aligned, Non-Aligned, -1, -1, 1, 1, Prime Minister, Prime Minister
Please let me know if I can be any more help. If I may ask, what brought you to Civ2 after all this time? Just curious how you heard about it. Thanks.