Considering level of research put into Osiris, all blueprints were classified to certain members of Liberty goverment (who weren't numerous). Who were either infected (and killed by the Order) or defected (the Order founders). Blueprints (as well as certain nomad-based parts of ship like cloaking device) were designed by the Order of Cincinattus, while construction was done by oversight of Liberty Navy & LSF (who supplied materials and were watching for any possible information leaks).
In that way the Order of Cincinattus got infected because they were working with nomads mainly. Later infection was spreading to LSF & LN high ups (who were mostly the ones who knew about Osiris).
Defecting (non-infected) part of the Order of Cincinattus managed to steal Osiris, destroy blueprints using covert agents and flee away.
With some time they managed to find Toledo, as well as establish some relations with certain Liberty officials who were indirectly supplying the Order with information, resources and humans...
