Welcome to Ireland Reaching Out!
I searched on the subscription site Roots Ireland and found one other baptismal record for a siblings of Thomas. See below. I did not find a reord for Thomas. Baptismal records for Kilfinnane RC parish start in 1831 and marriages in 1832. I did not find the marriage record. Here is a link to the parish register https://registers.nli.ie/parishes/0858 so you can search around 1845 for a record for Thomas.
Name:Patk. JusticeDate of Birth:
Date of Baptism:15-Feb-1835Address:GragueParish/District:KILFINNANEGender:UnknownCountyCo. Limerick
Father:George JusticeMother:Bridget CaseyOccupation:
Sponsor 1 /
Informant 1:Not RecordedSponsor 2 /
Informant 2:Julia Hannon