I know that you do not have the 'maint' password, but if you have the 'administrator' password you can navigate to https://sra-ip:9083 and then access the web based cli. From there you can run the commands 'cluster list' and 'vserver list' to access how you have your storage added, i.e. cluster IP addresss, admin user credentials, etc. Just make note of those specific details.
Once you have that information, you should just decomission the SRA 4.0P1 appliances and fresh deploy the 7.x appliances. Remember to also remove the SRA adapters from the SRM servers and then install the the 7.x SRA adapters. Be sure to also decommission any old instances of VSC 6.x in the environment as they will conflict with 7.x. If you are still using SMVI backups with VSC 6.x, reach out to your account team.
Once SRA 4.0P1 and VSC 6.x are removed from the environment, and VSC/SRA 7.x is deployed, you just need to add the storage back in the same manner as documented in your notes. If you add the storage in the same manner (cluster vs. vserver level) and use the same credentials, your existing SRM confugrations should not even need to be updated.