According to Bob Mannel's SBF book that setup was used on earlier 1964 289 HiPo and Falcon Sprints with the closed emission system which was required in California.
Bob, Look closely. I believe the lid has the hose fitting on it. Cobras didn't use a hose from oil fill cap to air filter, top or bottom.
Dan ,it looked like a seperate elbow to me straped to the hose and sitting unattached on top of the lid. I was refering only to the early style style rounded hump top as being appropriate when i posted. Now that I look closer it appears the elbow is attached coming out of the top of the lid. Thanks for pointing that out.Bob
With the hose fitting on the top, I believe that's an early hipo air cleaner for a California emissions car. guntrucker