Important notes: if you do rem ghost32 /setosdrives then you are running real risk of cloning over something you do not want. Winpe will mount volumes not in always a stable order, which means that your d: drive under Windows could well be mounted as e: under Winpe and e: as d:. Setosdrives removes all mount points assigned by Winpe and sets them to same as it was under "real OS".
Secondly, you cannot fool client agent - it has built-in mechanism to update itself so even when you uncompress WIM and install old version. Old version will connect and download new version from Console, including tools to run.
ghost.exe can not run under Winpe - it is DOS version.
Generally we dont guarantee that older Console can work with newer clients - we guarantee the other way round. This means that newer Console can always upgrade older clients to latest version. I do not know whether it will work the other way.
You should be able to connect GSS 2.5 ghost32 to ghostcast session from 2.0 builds without any issues (eg. manually starting up GSS 2.5 ghost32 under Winpe and connecting to ghostcast session or with command-line params) but not thru the Console - there is no guarantee of that to work.