It's been too long since I built it to remember where I got it. I can tell you the company that produced it was Wrebbit, that after a quick perusal of this forum and Papermodelers.Com, that there are a small number of threads related to Wrebbit products, and finally the impression I get from the perusal is that it is no longer made, but still available on eBay, Amazon, etc. I did a quick google and it did pop up for sale at various sites.
It's not the most difficult build compared to many of the things I have seen here, but it is one of the few paper builds I've run across that performs some sort of function when you are done building.
Hope you can find one. Enjoy.