The last plumbing task at the lake house was to get the water softener running again, and to fill it with salt. I was able to do this, although there are still some minor drainage issues to resolve for when the softener regenerates itself at night.
Regardless of that, all of the minor issues with the very old pressure tank, water heater, and water softener have made me realize that they should probably all be replaced this spring or summer. Once they have been replaced, all of the utility appliances will be new and I will have less to worry about in terms of leaks and other issues.
A future post will no doubt cover that process and the results once they have been replaced.