The man who did the home inspection to help us prepare for selling the house in the next year or so pointed out our fire extinguisher and suggested that it was old and should be replaced. It had been charged in 1976. We bought it because it was required to have in the home if you took in foster children. According to the gauge, it was still charged just fine. I didn't see the point of a new one. Ah well, home buyers are likely to object as well. Perhaps the gauge is stuck and the thing is now useless. I wonder how many years it was useless?
It worked fine, and I had fun practicing with it. I've got another on the tool bench, at least a decade newer. I'll try and get the granddaughters over for emptying that one.