If you have an annual travelcard on your Oyster is the gold card discount automatically added to your oyster PAYG? (With Oyster you get a separate paper 'gold record card' which alongside your oyster is classed as a gold card).
When I last looked at National Rail PAYG they had deliberately omitted gold cards from the list of suitable railcards that'd be recognised by PAYG - glad that was changed.
Do they still do the Gold Partner Card? Last I looked it was £1 and may be ideal for ajax, he buys an annual travel card and gets a gold card for himself (valid for up to 4 people travelling together) and one for his partner when travelling separately.