Leitrim-Roscommon

I am reserching the Nugent McMahon and O'Kelly Family's
Laurence Nugent was my Granfather and was involved in the war of independents, The Mc Mahon family are from Belfast and all but one (Michael) were shot during the occupation of the Black and Tans, Michael went on to marry my aunt,and Sean T O'Kelly's brother Matty Married another aunt, I am interested in any information on any of these people,

Thanks for any help.
Mags