Okay, I really want to know where the catalog number comes from. I can't see it anywhere on the packaging, and I've searched out some pictures even in eBay auctions and stuff. I haven't got a very clear shot at the discs but I can't make out any part that would read SQ108 (which is a really odd catalog number for an NTT Publishing release).
I see this number listed in a few other sites, but Daryl's Library explicitly says "No catalog number". A part of me feels that this number was just misinformation that started in one place and spread else where... but I guess Daryl's Library could be wrong.