Yeah, the best I know of, Puch did make the motorcycles, mopeds & scooters, for the Sears Allstate name .
back in the early 1960's, some guys, around here (Little Rock area, in Arkansas) would go looking for the Sears Moped gastanks, to use on their motorcycles. They were easy to mount, a single bolt, right up through the middle of the gas tank and with the moped's tool compartment, being at the topside of the tank, meant that the top of the tank was recessed, so the mount bolt was below the surface and couldn't cause any damage to the rider, in an accident. It also had a nice rounded shape to it and would hold enough gas, for a race. I remember them being used on the BSA C15 Starfire Scramblers that were raced, in our area and might have been others. Also, Cushman & a few others, were badged as Allstate. I had one of these tanks years ago and came across another one, a few years back. But, they weren't as big or nice looking as the one pictured in the original post. And nit to take anything away from what has been posted about the gas tank in the the original post either.