Glenn,
2 McManus farms in Crockadreen in the tithes in 1833, Patt & Hugh:
http://www.irishgenealogyhub.com/fermanagh/tithe-applotment-books/parish-of-aghalurcher.php
None recorded there in Griffiths Valuation c 1862. So they had presumably died or moved away. Death registration didn’t start in Ireland till 1864 and few RC parishes kept burial records, so tracing folk who died pre 1864 can be challenging.
There’s a number of graveyards in the parish that RC families might have used: Maguiresbridge, Aghalurcher Old, Lisnaskea RC, Tullynageeran & Cooneen RC. Cooneen might be the nearest to Crockadreen, though that doesn’t necessarily mean it’s the one they used.
I searched a newspaper archives site for mention of McManus + Crockadreen but did not find any matches. Aghalurcher RC parish doesn’t appear to have any early marriage records. Baptisms start in 1835.