You may be able to piece together the configuration from various files in $FWDIR/state.
However, it will be a manual process.
Check Point Professional Services can also assist with this.
However, if you want to start over, you can build a new management server and make a new configuration.
You will have to go to each gateway and use cpconfig to perform a SIC reset.
This will allow you to establish SIC from the new management server and push a new policy to the gateways.
Note that resetting SIC generally causes an outage.