How can this be shaped using only hand tools? Normally, a router comes to mind for something like this, or maybe a lathe, and then when you only think of hand tools, I think of hand planes like moulding planes, rounds and hollows, etc. But I've only ever seen those used on straight edges. It seems like this would be really difficult to do using those types of tools. Would they work, or is there a method to work with hand moulding convex curves like this?
Edit: This question actually comes from wondering how this was done in the 18th century. Wood turning seems like a good option, unless there are other ways to do it?