Thanks, everyone, for the responses.
Phillyg - Sound advice, of course. The axle has a 4,000 lb rating and our weight is always under that, so actually the 2040 lb rated tire would theoretically be acceptable, but the 2200 lb tire provides a much better cushion.
Mark Twain - I don’t think there are load range E 14” tires and moving to 15” wheels is not something I am planning on at this point. Certainly would be a nice upgrade, though.
Grit dog - I kind of figured the weight rating and psi capability went hand-in- hand. Thanks for the opinion on the quality of the Kendas. Good to hear that and makes me wonder if I would be okay putting a few thousand more miles on the 3 3/4 year old Kendas.
time2roll - You make a great point that I had not thought of. Using a tire size with a commonly available appropriate standard weight rating could certainly make an on-the-road replacement easier than needing to track down a specific tire from a specific manufacturer. I think this point really pushes me toward going ahead with the ST215/75r14, to get a standard 2200 lb at 65 psi rated tire.
Thanks again to everyone for your kind help in sorting this out.