Air Cleaner ID?

I stumbled across this '71 XR-7 convertible for sale:
http://wichita.craigslist.org/ctd/2853029840.html

I’m not in the market for another car, but I am curious; what air cleaner is this:

It doesn’t look like anything that was used in '71. Is it something off an older Ford? Vintage aftermarket? Or something more modern?

It looks to be late 50s to early sixties. Maybe T-Bird.

Buick used to use those on the nail head V8’s. They have been reproduced, and ols school Hot Rodders like them

Thanks. I thought I’d seen something similar on '50s Fords, but this looked different somehow. I’m pretty sure they didn’t have a connection for a PCV breather hose at any rate, but that may have been added. At any rate, I’d never seen anything like it on a Cougar before.