Here's a little trick to hide the "sewing" job, which is what the overlapping-plug repair is called. Use a portable sandblaster to rough up the block surface a little, clean thoroughly with a scrub brush and some high-pressure hot water and let everything dry well. Then spread a thin coat of Bondo over the repair, let it cure about halfway, and press a piece of 40-grit sandpaper onto the filler. The roughness of the sandpaper is a very good duplicate of the natural appearance of the cast iron surface of an engine block. That's a trick we learned on the round track circuit when modifying Chevy high compression cylinder heads to run in the "claimer" class by reshaping the ID tabs on the ends of the heads.
Jerry
