Freewheels with skiptooth cogs like that on the two largest gears, came standard on the Schwinn Sports Tourer brazed-frame road bike of the 1970s. My parents bought one new for my brother in 1972, and it had such a freewheel. My brother currently has no interest in it, and it resides in my garage when I'm not riding it around the local lake bikepath.

I figure there's an even chance that that one on Ebay, came off a Sports Tourer. I don't know what other bikes they came on (The ST's near twin, the Super Sport, came with a 14-32 that has 32 teeth on the largest cog, not 16). There was Schwinn Superior of the same era, basically a ST without a kickstand and with downtube shifters. Don't know if that one had the skiptooth freewheel or not.