The timeline you suggest is very interesting. Renaissance, early-mid 1800s, circa 1900. I wonder if you could do a series of minicampaigns in the same game universe at intervals of a century or two. Maybe it's a plane with a very high time rate that the PCs visit. (Think Narnia) Maybe the players belong to a long--lived race, or use some kind of hibernation technology. Or you play a descendent of your previous PC.
Very interesting indeed.
Are these books available as Print on Demand?