That would depend on previous owners’ or owner’s maintenance and driving habits. Piston-varnishing isn’t exactly an inspiring sign and the most wear an engine can experience is between cold start-up and having reached operating temperature. If the or all of the previous owners had a habit of driving the vehicle recklessly hard, during warm-up, doing so for 234k would likely warrant a preventative rebuild. The best way to quickly judge rebuilding or not would be to remove the valve cover and observe camshaft wear. If those look rough, you’d be better off doing them and that’ll give you easy access to pistons and bearings.
I once purchased a used ED-20 which was labeled to have had 194k, before it was extracted. The camshaft looked almost new, compared to my worn-out original which had only about 115k:
Of course, I’m not sure if that wasn’t a replacement engine or not, given that the vehicle’s odometer has no way of knowing. The piston to bore wear, however, looks like it has noticable side wear, indicating prolong periods of high-speed operation, since that’s when piston speed is at its highest. Whether the wear is excessive or not would be better off determining through measure and not simply visually