I’m surprised no one mentioned ansible yet. It’s meant for this (and more).
By ssh keys I assume you’re talking about authorized_keys, not private keys. I agree with other posters that private keys should not be synced, just generate new ones and add them to the relevant servers authorized_keys with ansible.
Do you want to supplement your usenet sources? If so, what type of content/language are you looking for? Do you have any proof like screenshots of the old times left?
Things that should be answered before anyone would consider giving away an invite, because that is also a liability.