I hope someone with a connection to the Curtis/McMahon family will be in touch. In the meantime please feel free to add your ancestor's details to our XO Chronicles Project. You can learn more about it HERE. It might be another avenue through which others can learn more about the family and open it up to a wider audience. As an aside, this is an interesting tutorial on chain migration you might find interesting. You might also be interested in this wider McMahon site, even though it does reference Co. Monaghan.