I still do not understand why you'd need to change the PGP file at all.
If others are using your machine, they should be logging into it using their domain credentials.
If the ability to change machines at-will is important, even if only in the event of a disaster so that each employees settings remain consistent, the profile should be loaded/updated from common network location, and individual custom settings should be stored to each user's personal network space and mapped accordingly.
This way, any user can log into any machine - be it for a project meeting in the conference room, or following a disk failure / machine replacement - and have their settings applied.