It's a fake. I got this off a Colnago Blog...
"I was very kindly sent a picture of a 'Colnago Tandem' from a reader in Taiwan. Whilst it caused a bit of a chuckle, I decided to do a quick Internet search to see just how many Colnago tandems where out there. So, please see below a few creations from around the world. "

There were pics of a couple other "Colnago" tandems as well.