No access to registered email, & wanna upgrade PT. DO have access to associated iLok

[SATP]

A client of mine wants to upgrade their version of Pro Tools. I have their iLok account name and password along with 5 of their registration forms which were filled out in 2004, so I have the serial numbers along with their auth code for their original Pro Tools installation. We no longer have access to the email address I believe the user account was registered in - email address may have even changed since original registration (don't ever let someone else register your products for you). I have tried password resets for the 2 email addresses of the owners, but there was never an accoutnt for those addresses.
Is there a way to find out what email address is associated with this information so I can move forward and try to upgrade to PTv8? (they still are working on original G5, so can't get to PT9).

Thanks for any advice

[zedhed]

If your client is unable to provide you with the email address I would suggest contacting Avid for support.

I would assume that they will be able to match serial numbers to the originally provided email address then realign it to a new one.