It has been 14 years since I posted my original post.
I can finally add some information and hopefully answers helpful to someone else as well.
1. Margaret, our Arnold's in Drumbrick are not related, but our Arnold's in Rockfield, Co Cavan are.
My great great grandmother, Letitia Arnold, shows up in the 1841 census as the sister in law to Charles and Elisha Elizabeth Houghton in Rockfield, Co Cavan. Your Arnolds are descended from William Arnold of Aghavadrin, Killeshandra, Cavan, Ireland. Children included Elizabeth, Rachel, Mary Anne, Richard and Letitia. The daughters were wed in Carigallen at the Methodist Meeting House. Richard was married in Co Fermanagh to a Margaret Johnston. Letitia eventually married Edward Houghton in Cloonboygher, Co Leitrim. I have recently messaged with a potential relative of yours-D and is very familiar with the Coromahon House as well.
2. The Arnold's listed by aghadowney are my granduncles and grandaunt. thank you!
3. Re the question of a Joseph Arnold existing, he does! His father was John Arnold b 1781. He was born in 1831. This is substantiated by his marriage records in 1854 where his father is listed as John Arnold of Drumbrick. He was still present in the 1901 census in Drumbrick. I also have DNA ties to John Arnold's brother Thomas and have been in contact with his descendants.
4. My Sherrard tie is from my grandfather from Limavady.
5. Thank you for all the info from the Leitrim Advertiser. I'm eager to go through them.
6. My direct Arnold descendants lived Drumbrick through the early 1950's. Several of them immigrated to the US, Mary Anne ARNOLD married and moved to Cloonboygher, but the rest lived out there lives there. I've hit a brick wall in that of the ones who stayed behind did not marry except for Margaret Jane Hyland nee Arnold, who died in 1954 at a hospital in Carrick on Shannon with her residence still listed as Drumbrick. She wrote my granny a letter with a picture saying that "Maggie had 3 sons". I can only assume that is her daughter or daughter in law but I can find nothing for her. Her father's name was John "Jonnie" Hyland of Druminshin Glebe, Co Leitrim, Ireland.
Thanks again for all everyone has contributed. It is so appreciated.
Marylou