Success, though it took about 1/2 doz. attempts. Guess I'm accustomed to pushing a button, and then a program does the work.
Did follow your instructions, however, could not find links, so, out of frustration, performed the (below) action.
Went to "itch.io/aground/download", where the original game was purchased, and took a chance at downloading the full 1.7.1 version. This worked, after re-reading the multi-prompts, and selecting the correct action(s) during set-up.
My biggest fear was that it would erase my present saves, and thankfully, it didn't.
[For your edification: I do have the itch.io client, which did not update 1.6.2 or 1.7.1]
Thanks for the assist.