My sister, Margaret Pyne Burzlaff, looked at the Catholic church baptismal records for Nenagh some years ago. There were about 10 people with the surname Pyne listed in the records for the 1790s and they were possibly inter-related. One of these was a Martin Pyne who was baptised in Nenagh on 23.10. 1794. His mother's name was given as Mary Pyne and his baptismal sponsor was Thomas Pyne, who was probably the brother of my great-great grandfather, John Pyne. This Martin Pyne may be the one you are interested in. I'm afraid that is all the information I have at present about Martin Pyne. If you go to the National Library of Ireland in Kildare Street, Dublin, you can access the microfilm church records for Nenagh from about 1792 onwards. Good luck!