Ok! I took a break, came back fresh and I do not think I have to restring it. No idea what happened there… the E sounded exactly like a C right out of the box and having difficulty getting the sound for the other I assumed they had been swapped…
I was gaslit by my own instrument. But while it’s not perfect, all of the strings are now roughly in the right ballpark.
I got this thing yesterday, it’s the first time I’ve ever had or tuned a stringed instrument, by ear, so I’m taking the win. 👍😺
I’ll still be looking at other tuning guides for second opinions or anything I missed. (This was done by open plucking of single strings.) I’m sure I’ll soon hear if it hasn’t been done properly.