Data loss Syncing issues with old iphone 2.1

My uncle has an iphones running 2.XX he has had it for many years. The first time he synced it he synced it with his friends computer taking some of his music and also purchasing some extra from itunes. He didnt sycn it again after this point until he go a imac a few weeks ago. when he synced the phone it removed all the contacts i managed to get the back by restoring from back up. Is it possible to sycn with itunes without losing all the music and contacts? bearing in mind the phone is not jail broken and he no longer has access to his friends computer.

Also if the phone was updated to 4.1 could the phone then be restored with a previous backup without losing contacts and music? I would like to do this if possible then correct me if I am wrong I could jailbreak and just access the music using ifile.

Thanks

any fixes?