No connection to auction except that I have a carb and intake just like this. Looks pretty nice and complete - between the fuel bowl and the throttle body is a small tube going up, there should be a brass screen wrapped around that, but other than that it looks ok. Obviously you wouldn't know for sure until you opened it up.
http://www.ebay.com/itm/Vtg-Antique-Brass-Zenith-Carburetor-S4BF-Model-T-Ford-Hi t-Miss-Gas-Marine-Engine-/390899777994?pt=Vintage_Car_Truck_Parts_Accessories&ha sh=item5b037141ca&vxp=mtr#ht_554wt_1363
I really love mine. Only 1 adjustment on it to set the idle, just bolt it on and go. I usually give mine 1 pull with the choke on and then 1 pull to start right up. I've never gotten beyond about half throttle (was going a terrifying 62 mph). Idles nicely, starts easy, and ads ridiculous acceleration and top end. As Stan Howe would say, zoom zoom!! Also at $500 Buy it Now and free shipping, that's a great price, at least to me. Granted, if the venturi inside is cracked and you need a new one then the price is a bit high. I would think it's probably ok though based on the pictures.