There isn't a automatic way to restore the avatar's, it needs to be done manually
I've copied across all the avatar's that were stored on the old forum, to access them go to -
profile > Personality > tick the use avatar box > then click change avatar > select default gallery for the avatars that were uploaded.
if your avatar doesn't appear in the gallery it must be on a external link, which at present I'm not sure if that's possible, if not you can upload your avatar, just click on the upload avatar link.
cheers
Lyndon
ooo and registered dates are fixed.