Beautiful pic of the nest Rob, very interesting to look at and see how they made it.
I had a wren that made up a nest in my hanging basket for about four years on the run, he made one every single year.
I swear each May he would sit and watch me make the baskets and as soon as it was hung, he was off, busy working away.
They never actually laid eggs in it as like you say they make ten or so nests and then the 'wife' chooses her favourite, but for some odd reason he did use it every day, he was always in there, particularly at night~maybe Mummy wren prefferred the single parent life ;D