I ran my gas trimmer by accident without pouring in my pre-mix of 32:1
gas to oil. The engine seized after about 30 minutes. Not sure if I
have to buy both a new piston/rod and cylinder assembly (about $50
total cost) or if I should just run out and buy a new one. Is there a
chance that more things are broken that what meets the eye such as
where the piston rod connects with the fly wheel.

Here is what I've done so far: when I pulled the cord, it didn't budge
an inch, so I took it apart and got access to the piston. Even with
coating the piston with oil, it doesn't want to move very smoothly
within the chamber. I'm guessing one or the other is warped. Physical
examination with the naked eye however doesn't show any such signs of
warpage nor any scoring so I'm not sure. Is warpage measured in
milimeters so that it is not distinguishable by just looking?

Anyone wanting to own up to a similar occurance would be most welcome.