A Call of Cthuhlu game just started although that isn't quite old but there are older versions of it. What kind of genre were you hoping to start? Scifi, medieval, mystery, super hero or something totally different? What about a Warhammer game can that be made Play By Post without restrictions?
I don't know, I'm just throwing out a suggestion for you since you seem to be undecided and its an Role-playing Game that isn't on this site yet.
The mechanics are pretty similar between the Fantasy and 40K. It is a matter of SciFi and Fantasy elements and preference.
Once again, I am happy to answer any questions concerning the two, in order to help others better understand. If we get to a point where others decide they would like to play, well great.
Name: Stephanie
Comment: Half the games these guys mention are still in print or with new editions. They need to put their ear to the ground more.
They are just trying to ascertain what serious players (Writers) want to play in a play by post environment, its not about being exact with what is not being published anymore. In the end it is about the passion of bringing your character alive through your written descriptions.