No telling on the age; it might be new. They aren't hard to make at all. Just grocery bags, a couple of coat hangers, and thinned Elmer's glue (wood glue & water based but waterproof glues for more strength and permanency. {slightly more brittle though})... Oh, if you ask, some grocery stores will have brown paper bags, the old standard. (maybe lawn & leaf?)
I'd say it is more prewar in style, as postwar tended to be pulp paper vs sheet paper and sheet tunnels went away first here. The last pulp paper tunnels I recall in stores vanished in the mid 70s as foam was more and more likely to be the only ones seen. (retail store shelves mind you, maybe not hobby shops.)
I've seen glue saturated paper mache, pulp paper, felt, woven cloth, even lint, lol . Close examination might reveal whats actually used.