Wexflyer, I’m afraid I did not locate the Wexford Gaol record but thank you for letting me know that that Jeremiah came from Cork.
I have a couple of people in my tree who’ve changed occupations through their life, and notice a lot of people with public house or brewing type occupations also do other work such as farming.
I’m not sure if farming was a step up from being a Tailor, however it probably was if it implied he was a land owner.
On arrival a number of immigrants told the authorities what they thought they wanted to hear when it came to occupations, as some were more useful to the colony than others, and at various times different occupations were in demand. Fibs are always very possible.
As we are having difficulty researching this family my second cousin once removed believes that the only way to progress is to go to Ireland.
I’m not so sure because I thought that where records exist, a lot would be digitised and accessible online. Would you say that is the case, or would there be useful records only available if you visited in person?
Presumably it is like all digitisation and is a work in progress, with some areas and time frames covered better than others, but what else would there be in terms of records? I’m thinking that apart from census (none for the time frame for this family), Griffiths Valuation, bmd/parish records/ baptismal records, newspapers and the criminal and court records you mentioned, that would be about the extent of it?
Thanks again. 
Quite a few points there!
First, as to occupation. This is just a guess, but I presume most emigrants to Australia went there to better themselves. To move up the social ladder. If your Dad was a tailor, did you want to go all the way to the Antipodes to be a tailor also? Probably not. You most probably wanted some - lots! - of all that vast expanse of land that they were giving away. And who were they more likely to give land to - someone with a farming background, or a townie? So, just a guess, but if you wanted to get a farm in Australia, was there an advantage to claiming a farming background?
As for records: Ireland is relatively good on digitizing what records have survived. That said, there are some that aren't available online. For example, the Darby Healy in Irishtown New Ross. The records of the Valuation Office in Dublin will show in which house he lived, and when, roughly he disappeared from the records - which is probably when he died. Should also show to whom the house then passed. Did it pass to one of his sons? When did they drop out of the records?
Then there are graveyards. Darby is must be buried locally in or near New Ross - is there a memorial? Lots still to be done on that.
But records are only one aspect. Is the objective to just add names and dates, or do you aim to have an understanding of where they lived, what conditions were like for them?
I am from Wexford and I know these places. That is invaluable to me in understanding the physical geography, distances, and circumstances in general. For example, if you were to visit New Ross, where Darby Healy lived (one of the few known facts), then you would find:
the same streetscape he knew, many unchanged since medieval times, many of the same buildings, the same church that he and his family must have attended. There is a replica emigrant sailing ship docked on the quays in New Ross, as a museum ship to visit. You could visit the local graveyards - he and his wife must be buried in one. Visit the possible townlands in the vicinity of New Ross that we identified.
