mdadm: after a re-install, two raid1 partitions were relabeled raid0 but the data are raid1

Maybe the simplest thing is to just mount one partition by itself read only and pull the little bit of data not fully backed up and rebuild from scratch. Otherwise, since there has been no I/O activity on the partitions since I shut down the old system, I was hoping I could just tell Linux, "no, those are RAID1 partitions" and mount the mirrored data. I haven't found a way to do either. :( I'm considering researching the format of the superblock and binary editing in the RAID level.