It's a bit of myth that people didn't grow old or live much past 50 years of age. It is true that life was hard, and retirement as a stage of life doesn't yet exist. Jim, like his son, would have been the village blacksmith.
Paul has taken over this role as Jim tends to do the lighter duties. I say lighter duties but pumping those bellows over and over again is no joke and very tiring work. His role, although less physical than the blacksmith, is still more than than most could do now. He keeps the fire in the forge lit and at the correct temperature and this is no mean feat. It involves pumping those massive bellows by hand and that, I can testify, is some cardiac workout. He holds and steadies the larger pieces of steel that Paul then pummels and shapes into place. With every blow of the hammer that steel resonates up the arm and so it takes great strength not to wobble or move the piece.
Jim makes sure Paul has everything he needs to complete his tasks. From the large water buckets to temper the steel to the anvils, hammers, tongs and other fabulous looking implements. He has been caught dabbling a few times and making repairs to armour.
As an elder in the village Jim has a lot of experiences and advice to offer, he will gladly enthral you with his tales of many battles, the time the arrows got away, or the time the man in charge of the black powder used the wrong spoon (that story doesn't end so well). He may even tell you about the time the bottom of the forge fell through and he burnt the lords grass. If you have some time to spend ask him, and as long as the forge is hot, I am sure Paul can spare him for a few minutes.
There is no pension pot, saving for later in life would have been a difficult thing to do as living hand to mouth is more of a norm. Jim still needs to work in order to have food, clothes, a home, shoes and well .... semblance of a life.
Evidence survives of men living well into their 80s working, even fighting, alongside younger men. William Gascoigne was 85 years old at the battle of Tewkesbury.