Dear Matt,
I was looking for a Robert Donworth/Dunworth ancestor from Limerick in my family research so have come across quite a few references to "Robert Dunworth." One whose dates match those of your post is Robert Dunworth who lived in County Limerick in 1901. He was aged 17 on the census. He wasn't on the 1911 census although his brothers and sisters were. There are lots of siblings, amongst them John and Timothy. If this is your family, then I have some interesting news from a military perspective as I have researched Limerick soldiers from WW1. This Dunworth family lived in Glendarragh, Monagay, Limerick. Please let me know if you think this is your ancestor's family and I can let you know a few more details.