I used a variety of things. One of them was a plugin for 7-zip that treats image files like archives - I was actually surprised, but it showed the CRC sum as one of the file attributes. Another was the Windows checksumming tool (I forget what it's called). I can get you the actual names of all of those and the checksums produced by my own rips later when I'm not sneaking posts in during workOut of curiousity what did you use to calculate the checksum? I just open the iso in something like Hex Workshop and select generate checksum. I'd be interested in seeing what the checksums were for your personal rips.
As for images I've found online, this is what I found for the ones on EmuParadise:
Standard Disc 1 and 2 releases:
Good rips, checksums for the extracted data tracks match my personal rips.
Memorial Package Releases:
Bad rips, can't even extract the data track from these as IsoBuster, IMGBurn, etc. run into corrupt sectors on both discs.
I also checked the ISO/WAV/CUE rip on GameTronik and the checksum for it matches my rips as well.