Is this the same as the SCSI id? Because you can manually change the SCSI id whenever you add a logical volume to a target. I do this when I set up autofailover (so that the dest. and source have the same scsi-id) so that the clients think that the primary and secondary targets are the same and don't get screwed up by a different scsi-id when failover happens.

If you can find out the old SCSI-ID, then just remove the logical volume from its target, then add it again, while changing the SCSI-ID to be the same as the old SCSI-ID.