Mike:
Welcome to Ireland Reaching Out!
I searched the subscription site Roots Ireland and they had an April 24th 1840 baptismal record for John Fury in Strokestown RC parish and also a Michael in 1845. See transcriptions below. I did not find a marriage record so likely the marriage occurred in a parish that does not have records back to 1839. It is possible that the Griffiths record in Kilglass parish could be your ancestor but I checked www.askaboutireland.ie and the landlord was not Mr. Sproule.
www.irishgenealogy.ie has the original civil death records online for free starting in 1878. We believe the records for 1864-1877 will be available online later this year. At that time, you can look at the 1877 record to see if it is your ancestor.
Let me know if you have any question. Have you considered DNA testing?
Roger McDonnell
Name:John FuryDate of Birth:24-Apr-1840
Date of Baptism:
Address:NgParish/District:STROKESTOWNGender:MaleCountyCo. Roscommon
Denomination:Roman Catholic
Father:Martin FuryMother:Mary DoorlyOccupation:
Sponsor 1 /
Informant 1:James Kelly Sponsor 2 /
Informant 2:Margt O Kelly
Name:Thomas FuryDate of Birth:14-Dec-1845
Date of Baptism:
Address:NgParish/District:STROKESTOWNGender:MaleCountyCo. Roscommon
Denomination:Roman Catholic
Father:Martin FuryMother:Mary DoorlyOccupation:
Sponsor 1 /
Informant 1:John Doorly Sponsor 2 /
Informant 2:Ann Doorly
Notes: