How bad did I #$&% my piston up?

Even though I bought a ring spreader in 1973 when I built my first engine, I never use it.
I think installing the rings by hand gives me much better control and is less likely to result in damage to the piston or the ring.
The spreader makes a great conversation piece hanging on my wall for people who've never seen one before.
I'm glad that your piston is ok.