This Gillette Knack is a P1, 1970. I found it on an eBay Buy It Now listing. I had been wanting to get one for some time, but I wasn't willing to pay what they were asking. It got this one and a dispenser of blades for under $13 shipped. So, I feel like I did pretty good. These first pictures are from the listing.
The next pictures are ones I took after I cleaned the razor. It is supposed to be a mild shaver. The long handle makes it a great razor for the ladies, too.