Definately measure it to see if it's in spec.
Just recently I had my machinest measure a standard bore XR600 cylinder I've had kicking around for a number of years. It looked great. I figured I'd hone it and use the 10.8:1 compression Arias piston that came out of it (it looked great as well) and be good to go. Wrong! It was way out of spec in both size and roundness.
So the moral is, just because it looks good doesn't mean it is.
2005 KTM 525EXC-2000 Buell M2 Cyclone-1996 XR600R-Plated 1995 XR600R-1993 Kawasaki KX500-1984 Honda XL600R/XR650L Hybrid-1984 Yamaha TT600L-1980 Honda CB750F