I can answer most if not all of it actually, because I was more invested/interested in this and unlike the jazz 2 beta I talked to the source often here.

While with the Jazz 2 Beta I have not talked to the source at all, it was all Bryan doing the talking. Just sometimes he forwarded my questions.

Okay, so your question what this consists of, that is partially correct, however the old beta build has two swappable set of files so it basically consists of two
builds in practice...

I have constructed my tree with different system and map directories for the swap versions...

Unreal Engine does allow that kind of thing by modifying the config files to look for different paths.

However your assumption about the common Jazz 3 leak is incorrect, I included it within my tree so there's the complete catalogue.

This was not provided as such by the source.

Next, don't look at the engine numbers here. This is a crucial mistake, as this is not a game with its own engine.

This means that Jazz 3 was at those stages developed primarily (with different dev cycles) on two Unreal Engine versions only.

Version 224 and later, 400. The 400 Calypso one is thus a different worked-on version than the common leak.