Callaghans emigrated 1825 aboard Regulus (Peter Robinson) to Canada

Hello:

I would like to find out more, if possible, about the ancestors of my surname. They were listed aboard the Regulus in 1825, part of the Peter Robinson settlements, to Ontario, Canada.

The confusing part is that a tombstone in Downeyville, Ontario, say clearly that they were "native of Tipperary", but listed officially as being from Mallow, Cork, and the name C.D.O. Jephson was given. Jephson was a large landowner who I believe had the seat of his estate in Mallow, and I do not know if he sponsored them because they were farming on his land, but I assume this must have been the case. They were listed as "reduced farmers". This included Jeremiah and wife Kitty (I believe Murphy), children John, James, Michael, Mary, Ellen. (The family is recorded as an example of the Callaghans who emigrated, in a book about the entire history of the Callaghan surname, written by Joseph O'Callaghan).

Jephson undoubtedly owned a large territory. I am just making guesses as to whether they moved from Tipperary to farm near Mallow or whether Jephson's territory extended into Tipperary and they farmed there, but for brevity their former residence was just put on the ship's register as the address of the central, official house of the "lord" whom they worked for/rented land from (and I would love to know what their status was and what "reduced farmer" meant).

It is James who is my ancestor, and it is his tombstone (rather than his father's) that says he was a native of Tipperary. Yet he was age 10 when his father Jeremiah, and mother Kitty, brought him and siblings to Canada. That would not have allowed much time for him to be born in Tipperary, before his family moved to Mallow to farm, and then left for Canada. It seems doubtful that the family and friends who buried James got his native territory wrong. It could be that Mallow is a mistake, or an approximation, just to put something down on the ship's register, or it was where they had been living before they left. Others on the same ship, listed under Jephson, have distinct other towns in Cork, so some care seems to have been taken to be precise about where the families were from. A relative who did some research said they may have been from Clonmel, but she has passed away now, and I do not know what led her to believe that. She was not sure.

When I was in Mallow 2 years ago, I asked at the heritage center, and was told that it was unlikely that there is any information going this far back. Birthdates were 1790,91 for the parents, and between 1810 and 1822 for the children.

My question is: is it worth pursuing? And if so, what would I do? Should I post this message in the Mallow section? I could search for information in several parishes of Tipperary, close to the Cork border (Templetenny, Shanrahan, Tullaghorton, Barrettsgrange, Clonbeg, Killardry, Caher, Ballybacon and Tipperary South, are the parishes close to Cork), or I could search in Mallow. Is it the case that church records do not extend this far back? Would children born 1810 to 1825 be recorded somewhere?

Relatives I may have in Ireland related to my surname would be so far removed, I am not really hoping for connections necessarily. But at the very least, it would be interesting to know where they were from, and more about the meaning of their status as reduced farmers. I visit Ireland often and it is possible for me to do research but I don't know where to begin.

An aside: as a 3rd to 4th generation Canadian, it is hard for me to pick a parish to belong to because there are about 10 separate ancestors, hailing from counties across Ireland, of various stripes (Catholic, Protestant Presbyterian, Methodist German refugees from Limerick) who met and married, and whose descendants met and married, in the US and Canada.

Thanks kindly for any advice or any comments or information anyone might have!