Push Notification Certificate Key

I know this doesn't answer your question, but what are you trying to do?

a general question for manual recovery a JSS without the Backup.

I had always believed the only thing you really need is the mysql database. There is the jks store if you have 3rd party certificates. I'm guessing it's one of those two places, but I really don't know.

Both the 3rd party certificates and Apple Push certificates are easily re-created, you may need to re-enroll all your clients... but that could be done with another QuickAdd package, SSH, or use https://jss.domain.tld:8443/enroll/ URL.