Dunlop "Giant" Foot Pump

Dunlop "Giant" Foot Pump

I loved restoring this one and it was a lot more complicated inside being a 3 stage pump , This was pretty large and heavy but was capable of 300psi when I tested it {stopped as I was getting scared} , Not sure what age/era any help ?

I sold this pump and the Person was going to display it with a vintage truck which I was very happy about but regret selling it !