I'm AFPC right now, but I believe all the data maintained by VA is kept in VoiceAttack.dat files housed in the VA "Roaming" folder within your user "AppData" folder.
There should be a Backup folder along with a main *. dat file. As a precaution make a copy of the main file then go into the Backups folder and find a *. dat file with a modification date that corresponds with the profile version that you want. Then simply rename this particular dat file to be VoiceAttack.dat and overwrite the main file in the parent folder (do this with VA not running). Then simply start up VA and you should be able to view the previous profile. Note though that this will also role back any and all profile changes to that modification date.
I like to keep track of revisions on my more elaborate profiles so I often create exported backups of those profiles. Also helps create an added redundancy in case the *. dat files ever get corrupted.
HTH!