Thanks very much for the clarification. I had wrongly assumed that since the user and hostname was added to the key file upon creation, that it was mandatory info. This makes things much easier.
Also, thanks for the warning and suggestion regarding users being able to login in as other users. I'll keep that in mind.
Thankfully, in this particular setup, each client workstation has a scripted login and the workstation is highly locked down. So much that the user cannot run anything but a preset choice of 3 shell scripts, and a web browser.