I just wanted to close this loop by saying this I'm almost 100% sure this is the correct Charles Smith. I noticed in the original 1871 census image that his occupation is listed as "engine fitter." That's what his occupation is listed as when he joined the Navy in 1881. I think that combination of matches makes it pretty clear that it's the right Charles Smith. So, thanks again to Rob and Linda for helping me track this down! --Jessica