Further found Thomas Patrick McCarthy's wedding to Margaret Begadon (14 Jun 1922 at St. John Clontarf).
Margaret Josephine married Joseph Fay 22 Aug 1923 at Church of the Visitation in Fairview Dublin.
Haven't found the rest yet.
Edit: Found a grave belonging to this family group in Bray.
http://www.igp-web.com/IGPArchives/ire/wicklow/photos/tombstones/little-bray-3/target113.htmlBut it's throwing up a red flag on these last two marriages at least. Thomas and Margaret are linked by the address of 70 Cadogan Rd., Dublin. Both of them had this as their address at time of marriage. On the St. Peter's Little Bray website, they've got a burial index which lists addresses for the deceased, and this grave is clearly associated with that address.
BUT- as you can see, there is a Rose McCarthy included on the stone. I looked her up after looking Thomas up. She is clearly his widow. On her death record, Thomas signs as her son. This doesn't match Mary Lawlor, unless it's Mary Rose Lawlor. Her age is also about 6 years younger than the original Mary. Thomas also appears to sign as Thomas F. rather than Thomas P. as we'd expect. The elder Thomas was listed as a farmer on Thomas's marriage to Margaret Begadon. That's a little weird for him, I think, but when Margaret got married with the same address, I was reassured to see him listed as as "retired official," which matches well with the census record above.
I think at this point John's marriage is the only one I am confident of.