Audrey,
If you're searching for Protestant churches in Muckno parish, the registers of St. Maeldoid's Church of Ireland in Castleblayney begin in 1810, and they are in local custody. You can write the current minister and ask about entries on your STEVENS family; there's a typed abstract of the register on CD in the church office which the secretary would check for you. Also you could ask a volunteer or paid-researcher to check those records for you on-site, where he or she might perhaps view the original register rather than the typed copy (which is liable to errors in transcription).
Presbyterian records of Muckno parish start in 1820 (Frankford) and 1832 (1st Castleblayney). Both are on microfilm at PRONI in Belfast.
Catholic registers of Muckno parish begin in 1835. I haven't checked their location since I've only looked up Protestant records in Muckno parish.
These church register dates are from Brian Mitchell's "A Guide to Irish Parish Registers," which is an excellent church record source book, even with a few errors here and there.
Good luck with your search,
Annie
