What you can try, is to boot the system off one of the old install CD's and try it live. If it works, have a look in a konsole as the output of the command lsmod. That will list all the loaded drivers. The list may be rather long.
Another solution is to run the printer in with V-box. Not ideal, I do that with my flatbed scanner since there is no linux driver.
Have you had a look at Ubuntu forums for a solution?
I didn't add any drivers?
The printer was probably detected during the install process, and the driver added then.