@miles after restoring the secret file, you have to start gossipping with peers to resync the database.
Either:

1. Have another peer on the LAN who follows you (maybe)
2. Manually make a gossip connection. e.g.:
   sbot gossip.connect 'net:ssb.celehner.com:8008~shs:5XaVcAJ5DklwuuIkjGz4lwm2rOnMHHovhNg7BFFnyJ8='
3. Restore your old ~/.ssb/gossip.json file, or get one from someone else. Then restart ssb-server