Looking for info about these vintage Federal HI-POWER 20 Gauge

Hey all, I came across these shells while cleaning an old barn out that I was told has been standing since the prohibition days. Among other items that were clearly antique was a stash of what I assume would have been quite valuable magazine/tabloid type print publications from the JFK assassination in '63, if they had not been soaked in animal urine and feces. I only mention them in the hopes that it might help narrow down the age of these 20 guage slugs. I’ve scrolled through Google results un

Federal Hi Power 12 Ga Plastic Shells Full Box

Vintage Federal Hi-Power Shot Shells 20GA Empty Ammo Box (Gold

Vintage Shotgun Ammo & Shotshell Boxes For Sale

Lot - 10 BOXES VINTAGE FEDERAL MONARK SHOT SHELL BOXES

Vintage Shotgun Shells: Federal Monarch Hi Power

What Happened to the 16-Gauge Shotgun?

Looking for info about these vintage Federal HI-POWER 20 Gauge

Vintage shells. Safe to shoot? : r/Shotguns

100 Iconic Loads from Federal's 100-Year Anniversary

Dunkelberger's Sports Outfitters - We buy used guns and gun

Product Preview: Federal Premium Heavyweight TSS Shotshells

Empty Shot Shell Box

Tungsten Super Shot - The Evolution of TSS Shotgun Shells

Vintage Federal Hi-Power Shot Shells 20GA Empty Ammo Box (Gold

Lot Detail - FEDERAL HIGH POWER 20 GUAGE 2 3/4 MAGNUM SHOTGUN SHELLS