If it were my I would as Joe said get the aussie made block.If not I would rebore it and put in an oversize piston.Sanding it wouldn't work scores to deep and I'm thinking if you could get it to anything it would only lose it's roundness and turn it more into an oval shape.Which would lose compression.I had two similar engines here not long ago,but they weren't as new or as good.I just tossed one mower and the newer one I just put a second hand engine on.
