Great job!
But I like a longer board because when I buy fabric it's in 3yard lengths most of the time, and that leaves me with one question, "Where or how to store a longer board when I don't have space to leave it out" That brought me to my own answer which I thought I'd share.
Instead of one long piece of wood 48" long, I would use two that are hinged (using a flat type of hinge) together so it could be folded away when not in use. You could also put folding legs on each end for added support. And like someone mentioned earlier, put rails on the under side so the center would sit on your normal ironing board.