You can then put the recovery seed into an offline copy of: https://iancoleman.github.io/bip39/
There are instructions at the bottom of the page for downloading etc
Put the seed into the "BIP39 Mnemonic" section at the top. Then click "BIP32" under Derivation Path, set "Client" to "Custom Derivation Path" and set the "BIP32 Derivation Path" to: m/0'/0
All your addresses/keys will be displayed at the bottom.
NOTE: You may need to click "show more" to see all your addresses if you have used more than 20 receive addresses... and you'll also need to set the "BIP32 Derivation Path" to: m/0'/1 to get access to your change addresses!
Thanks HCP. I've also been meaning to do this for a while and will give it a try.
The protobuf format is reached once the format has been decoded from the password isn't it?
EDIT: It worked, even with the encrypted one.
A good thing to note is that you first use the default setting on "BIP32 Derivation Path" to get the regular addresses before the change ones.