I have managed to get some life back into really dud battries. I suppose like most things if you start using the charger on a reasonable battery you will improve the life.
The bolt action .22 may well have been a Mossberg. A lot went to cadet units, that's where mine came from. I also have a .22 Enfeild No1 completet with the toys. That was made about 1903 for cadet units.
The Royal Navy didn't stop using them till about 1970. As the Gunnery instructor told us 'They thought they had plenty of stores. Didn't count on people like me using about two thousands rounds a day for personal use'.
My Mossberg has the same. The US was Neutral and there fore could not sell equipment to the British. However as Rossevelt said 'If a man's house is on fire. you'd lend him a hose pipe'. But you cannot Lend or Lease equipment, unless you can PROVE it is yours! Hence the markings (Wonder if we now both get snotty letters from Washington? ) My Mossberg dates to a batch that arrived February 1942, so your Savage must be around that date or ealier. Post 7th December 1941 Germany had declared war on the US so the need to mark did not apply.
A lot were manufactured overseas, Canada, South Africa, Australia , India. They would have back to the country of origin and a lot of them are still shooting.