I was quite disappointed that I could not make a custom civ the first time I played civ 3. But I soon found out that I can edit that in the rules.
I always play the Romans in all civ games. Always. I like their city names, and I like Roman history. But I also want to try out different civ special abilities, and unique units

so I edited the rules to give the Romans different abilities every time I play, and swap unique units with other civs. In the current game I play, I gave the Americans the legions and gave F-15 to the Romans

.
Why can't I do this in game? There is a random button, but I don't see the custom civ button? Or did I miss something?