This would have been more or less routine except that one of the five captive screws that hold the heat-exchanger assembly in which the heater core lives had rusted as well and wouldn't turn properly. The nut needed to be ground off, and it was in a very tricky position. She got out her Dremel tool and started grinding, with me to help fetch and carry as necessary.
It took more than two hours to grind it off, with Lisa in an awkward, uncomfortable position the whole time. With the nut removed, the assembly finally came off, and it took about fifteen minutes to replace the rusted-out heater core with a new one. Of course, she can't put the new assembly back into place until she gets a replacement for the rusted holding screw and nut. Also, it would be really nice to replace the gasket, but finding a replacement heater core cover gasket for a 1976 Ford E150? Goodness only know how we'd do that. Online searches aren't turning up anything close to what we need.
After hours of fussing with the engine, Lisa went to take a break. As she walked toward the front of the house, her ankle turned and she took a tumble. I came running. Two Lyon County Sheriff's deputies who had been having a car-to-car conversation a block away drove over as well and asked if we needed a paramedic. Lisa said no and I helped her to her feet. Her ankle hurt quite a bit, but she managed to hobble around a bit and we got the van more or less secured for now. (But it's still not drivable, and has no coolant in it because she had to drain it to get the heater core out. It's not good to let the engine sit with no coolant in it.)
While Lisa had been working on the van, when she didn't need me, I was using a newly-purchased Hula-Ho® weeder to dig up the weeds growing along our sidewalk. This worked quite well, and I'm pleased with the result. We'll never make the pages of House Beautiful, but I like having those weeds gone. But not long after we knocked off work, my back started hurting. And two days later, it still hurts, but I'm not as bad off as Lisa is.
Not long after Lisa de-kitted and we put away the tools, it became clear that her ankle was in much worse shape than we originally expected. It's not broken, but it's a bad sprain. She's wrapped it and is trying to keep it elevated. I eventually found the crutches we have in the house, and she's hobbling around on them when she needs to get around. This isn't the first time she's injured that ankle, and she reckons she'll be off her feet for around a week.