Can a GPO'd install of Office 2003 be SP2'd by another GPO?

[-=gu=-]

All our XP clients (40 of 'em) had Office 2003 installed via GPO, having used
ORK to customize the install. When Office 2003 SP1 came out, I manually went
around and installed it on everyone's computers. Now I'd like to install SP2
on all those workstations. So...

For SP2, can I:
Install our Office 2003 image on a clean machine and then use Winstall to
create the SP2 delta, then deploy it to users (after testing) with a GPO? Any
reason I can't do this?

I have found very little on any sites or searches (including MS) as to
handle SP2 when Office 2003 was originally installed via a regular Group
Policy Object.

Thanks!