This didn't seem to get much traction on here, but if anyone is interested I've done some major digging into what was released, including finding older builds, a patched/bugfixed version of the original OCS game that was never released, info on the AGA/CD32 version, unreleased maps, and the original Map Editor complete package including manual and surrounding tools that seems to have never been actually released.
https://tcrf.net/Hired_Guns
https://tcrf.net/Development:Hired_Guns
https://tcrf.net/Proto:Hired_Guns