There was a post a few months back where someone made a deck ext for a double console. It was longer and had a end cap on it. Someone may come by the info and re-post it. It may give you some ideas on how to make one yourself.
My single console has a homemade 3 sided box that sits directly behind the original deck.The box suports a lid which is piano hindged to the original deck.It is all covered with carpet and look very nice.Makes for lots of extra storage and a full sized deck.Will try to get you some pics if interested.