Also, if I am to start bitcoin core with -salvagewallet can I do that thru the RPC console
No, it is not an RPC command. You can't start Bitcoin Core with that option through Bitcoin Core's RPC console.
or do I run bitcoind and do it from there?
No need to use bitcoind or any RPC command.
Go to Help > Debug Window and click the button to open the bitcoin.conf file. Add the following line:
salvagewallet=1
Restart Bitcoin Core. Once it has restarted, you will want to remove that line from the bitcoin.conf file otherwise it will attempt to salvage your wallet every time you start Core, which is bad.
If I am understanding you it would seem that the salvagewallet command should be given before startup? Which would be bitcoin-cli or bitcoind perhaps?
Again, it is not a command, it is a startup option.
I don't have a backup wallet dat file from before this all started to take place unless bitcoin core does periodic backups on it's own which it probably does not.
It does not make backups automatically.