...and now you know why my Mama was muttering under her breath. That's a lot of blades to wipe clean of greasy kitchen exhaust. I'll say it again, though, it was effective.
We managed to snag a "new-never-installed" NuTone in-wall fan from 1957 for our kitchen (found the date of 17January1957 stamped on the inside of the housing). It's got an electric timer-dial control instead of a pull-chain, and the louver on the outside housing snaps shut strongly when it's off. Since the kitchen is pretty much "on hold" while we work on other projects, the fan is still in its box, but I was able to hook it up for a moment to see how well it did its job, and as Hazel would say, "It's a doozy!" The outer housing got bimped sometime in its life, but it will be too far off the ground when installed to notice from the outside. That grille is still perfect, and that's what matters. Upped three pics of it to our album.
For those that tire of cleaning grease from the blades- There IS an optional metal mesh filter designed for the majority of the round Nutone vent-fans. In fact, I even spotted replacements at H*me Depot last year.