Thanks for your reply Sinann.
There was an ad in the Limerick Chronicle 26/10/1842, which states that John has taken over the business of his father, Richard; Thomas-street is mentioned as the address, so I know that he was Richard's oldest.
Also, I think that this might be John's mother's Death Notice:
Limerick Chronicle 21/2/1824:
Yesterday in Thomas-street, the wife of Mr Richard Hunt, Merchant Tailor.
I think that this is Richard's second marriage:
Limerick Chronicle on 3/11/1827:
Mr Richard Hunt , of Thomas Street, merchant-tailor, to Bridget, daughter of Mr Thomas Ryan, Grocer and Spirit merchant, Mary Street.
But, assuming that the above is correct, I cannot find Richard's first marriage!