Thanks to Andreiuta I received the code and managed to use it successfully. If there's anyone left who's interested in this bundle please PM me. I have the code for the next in the chain.
For future reference the system advocated by weedfreak above works beautifully. I actually used an existing throwaway account but it would work fine with a fake account as a copy of the code is sent to the person making the purchase.
If everyone involved ensures that they generate a new code on checkout (whether there is an existing next recipient or not), then there is no reason the chain should die.
Thanks again to Andreiusta.