I had a pair of steel Power By Ford valve cover that came off a 70 Ford 351C. They had the drippers inside them.
I was under the impression early (70-maybe 71) 351 C steel valve covers had drippers.
351C, 351M, 400 valve covers will interchange. The "Oil Drippers" (deflectors) were in the aluminum valve covers for the Boss 351 because of the solid lifters requiring adjustable rocker arms. All other engines ran hydraulic lifters and a oil deflector that was between the rocker arm bolt and fulcrum.
This is a great site for learning new things. I knew the early 69 Boss 302 came with chrome stamped steel valve covers with deflectors in the covers for the oiling of the rocker arms. Then the later models had the aluminum covers with the oil deflectors we're used to seeing on the Boss 302/351. My first Cleveland powered car was a 1970 M code Torino GT (built 6/70). It had oil deflectors on the rocker arms along with both of my 1971 M code Mach 1's. So you can see where my mindset came from.
Even though all the rocker arm hardware ( rockers, fulcrums, deflectors, bolts, etc) had DOAZ, DOOZ, (1970 Part numbers) evidently the early production models had the oil deflectors in the valve covers such as yours.