There's nothing to get back, unfortunately. The process of moving over all of the posts had to be done without the user profiles in tact.
The current UBB.classic implementation of Groupee can not associate an existing profile with a new Groupee profile. The fix for the problem is a little on the complex side, and will occur later on. Of course, by then it will be a little on the late side. <img src="https://www.ubbcentral.com/boards/images/graemlins/wink.gif" alt="" />