There might not be enough to get e.g. one of the private keys, but you could probably use it to check for someone else in the contact list. The CRL also seems

There might not be enough to get e.g. one of the private keys, but you could probably use it to check for someone else in the contact list. The CRL also seems like it might be possible to at least pivot off of, at least if the signing wasn't checked when writing the archive.