OP does NOT need a 3rd party to recover a seed.
What OP needs is access to his GA 'secret key'.
OP currently is in possession of 1 private key (and 2 out of 3 are needed to sign a transaction).
1 Private key is lost since the seed has been lost and 1 private key is held by TrustedCoin. He just needs to retrieve his GA code to authorize TrustedCoin to sign transactions.
What do you mean ?
The GA is just a 2FA. It does not store any bitcoin-related seeds.
The secret key from GA generates one-time-passwords based on either a counter or time which are needed to authorize TrustedCoin.
This is not related to a private key or 'seed'.