What paint do you think would work under tung oil? I'm thinking watercolours would run but they might also just stain it nicely (of course they also might bleed along the wood and be impossible to make sharp lines with) acrylic might work but might affect how the finish adheres and I'm not sure acrylics will look "right". Is tung oil something that needs to be applied only to raw wood and I'd be better off going with some water-based urethane over paint? Should I just skip the painting entirely. Which look do you think would be more in keeping with period wood treatments?

While I've got you on the line to pick your brain... would you advise using softwood or hardwood for children's toys? I'm thinking hardwood *might* hold up better to chewing, then again teeth are going to be stronger than any wood so maybe it's doomed to get marked up either way. You've got a LOT more experience in this area than I do so I'd love to hear your thoughts.