In 2003 the rockers were changed to use a slightly larger needle bearing (same size outer diameter) because they were prone to failure.
I think you can use the 03 or 04-08 Husaberg rockers. You may have to drill a oil jet hole in them to match your rockers. Then you can easily replace the cam follower bearings with the available new type whenever needed as they are still available from Husaberg or KTM I believe. KTM rockers from the RFS motor may also fit and save you some coin. See the KTM manual for the 2007 525 that is
Hopefully Taffy et al will come along and provide exact fitment information for you.
Do a search on this site and you will find a wealth of information to study.