Fascinating post.
The breaking of Enigma was a huge success that likely shortened WWII by at least a year or two.
I'd like to see our computers attempt to decipher the remaining Venona transcripts - if they're capable of doing it.
The vast majority of Venona transcripts were never broken or only partially broken. It would be interesting to see the level of Soviet infiltration (of the US) during WWII and shortly after.
I think it would be much worse than we know.