I promised to follow up. I had some things come up so only just today got back to the pool. I emptied it all the way out but could not get the wrinkles out, even though the liner is pliable, it just didn't work, even though someone was helping by pulling it out from the wall to give me something to grab on. It was like the liner was too narrow. I did try the plunger, but the size of the liner seemed to have changed, so the wrinkles would not stay gone, they would just reappear or move sideways.

I had finally decided that by mid-June, it was best to live with it and move on. The wrinkles did improve, though, which was nice. I rented a 'trash pump' and filled it from the clean creek right next to the house rather than spend days gingerly filling it with well water and worrying about using too much.

Thank you to everyone who offered their kind help and time!