I'm probably repeating stuff you already know. Quick check of British Newspapers shows, in chronological order,
1889 - John Panepa receiving first place at Drumgold Street school boy's department (Herbert Panepa also got an award).
1890 16 Aug a boatman named John Canepa acted quickly to save lives " While two visitors were landing from a rowing boat at the Villiers Steps they overbalanced themselves and fell into the water. A boatman named John Canepa jumped into the water and brought them safe to the shore little the worse for their immersion".
In 1892 Joseph announces his new fish shop at No. 7 Windsor Road.
In Mar 1895 they publish a memorial to their father "In loving memory of our dear father Lazarus Canepa who departed this life at 12 High Street Oban Scotland on Friday March 16th 1894, aged 67 years
For fear, dear friends you would mourn and weep
While sweetly in the dust I sleep
And when you come my grave to see
Prepare yourselves to follow me
Prepare in time, make no delay
For I was quickly called away "
In Nov 1895 John purchases at auction 99 Castle Mona Ave for £306 (7 bedrooms, let for £18 a year.