I tried Gordon's method and it worked for me, but there's more than one way to work round the database, that's part of it's wonderful strength.
I could see the necessary figure quite easily, and I know the Unicorn knight also has golden armour.
In short Mike, to put you out of your misery, you'll need to buy a whole figure to get the arms, and disassemble it if you wish to use them on another figure.