Just to clarify:
Your old setup was a NCP with NC 23.0.6. You had a backup of the database and configuration of Nextcloud but not the data itself which are on your external drive.
You reinstalled a new NCP on the SD card and tried to restore the NC setup.
Problem the new NCP version has a php version that is not compatible with your “old” setup (NC 23). I’m not familiar with the details of the NCP system (Staying up to date), but there you could try to upgrade Nextcloud (not the NCP system) to NC 24 which should support your php version.
AH01753: access check of ‘localhost’ to /ncp-output.php failed, reason: unable to get the remote host name
Did you set up a hostname, and reset everything correctly on your router that you can reach the device over the network?
What I would do first:
Check on your data dir
/media/myCloudDrive/ncdata/data
That there is still all the data. Make a full backup, save the config backup and your data somewhere outside the system, that you can always go back to the current situation. Fiddleling around with updates in different orders can be a bit tricky and you don’t want to loose any data due to this.