You gave me an idea with the n-number. According to the FAA registry:
Red Eagle - N77MN - is listed as Pitts S-1T, s/n 1040
Blue Eagle - N49332 - is listed as Pitts S-1T, s/n 1039
Theoretically, if all three were built at the same time, then the other one would be either s/n 1038 or 1041. The FAA registry does list both as Pitts S-1T.
I found a photo of s/n 1038, N49331, but it has the standard factory red paint scheme. Obviously it could have been repainted or rebuilt completely.
The n-number for s/n 1041, N218MC has been deregistered. This could simply be because the renewal fee was never paid, but I didn't see any other n-number for this airframe.
Sorry, but I couldn't find any additional info.