One question is what would be the best wargame rules for the period from 1870 to 1905?

Perhaps lumping 1870 together with 1905 is inappropriate, but some fairly old ships were still in service, at least up to 1904, when they were finally hulked or scrapped. I would like to find a copy of Fred Jane's naval wargame, as I would like to see what he was doing. I suspect that we could figure out a way to improve on his system for shooting. He was a successful wargame designer in that he sold quite a few sets of his game and some important people played it.