Cannonmn, As soon as I saw that sprayer head, I knew I had seen it before. The ones I remember looked exactly like that rusted one you posted first, not at all like the smooth Stainless Steel model. The only thing anyone could complain about would be the orifice dia., but who knows, maybe the manufacturer ordered special large orifices or maybe not, after all, it depends on how tenacious the tank surface crud is that you are trying to loosen and flush away. You may want a gentle spray or a small orifice, high pressure, cutting, type of spray.
I will not say I am 100% sure, just that I am very, very sure. After all, I got the I.D. of the two cannon located at the Old Stone Fort wrong in 2007 when Mike and I went through New York on the way to the New England states. I told Mike as we went from Cobleskill toward Schoharie, that I remembered two 9" Dahlgren Guns from a school field trip being in the front yard of the stone church that was used as a fort when the British allies, Joseph Brant and his Indians attacked the colonials in 1780. When we got there, Mike strode up to the cannon and said, "9" Dahlgrens, eh? I don't think so." I took a quick look and agreed. They both were Bureau of Ordnance, 32 Pdrs. Hey, it had been 50 years plus, and the shape was very similar! I am not infallible.
Tracy