I own a version of ACID 4.0 that includes Sound Forge V10...the numbers I have do not work. There are no support services that I see for finding the proper serial #. I do have the Sound Forge order #.
Welcome to the Sound Forge forum discussion group @Scott-Nelson .
Sound Forge and other SCS (Sony Creative Software) product serial numbers were transferred over to Magix in 2016 with the acquisition. You can try looking on the "My Products" page in the 'Magix Service Center'. You will need your user name/email and password to log-in. Otherwise contact the Magix Customer Service Sales Team which handles activation issues and such.
You can also try your SCS log-on info if you still have it,