Server 2003 sp1 updated to sp2 ASR

We have about 150 servers running 2003 sp2 (NOT R2) that was updated from sp1. I am trying to do an ASR but I am unable find a sp2 install disk. I tried using the sp1 disk but when I do the ASR it gives me the error of needing original installation media. I tried slipstreaming sp2 into the sp1 disk which did not work.

Does anyone know where to find a 2003 sp2 (not R2) disk or have an idea how to use a sp1 disk to perform the ASR?

Thanks

JC