Thanks JM and Annie, I'll get onto those.
I just found a Joao INACIO and Louisa CONSTANCIA, both born Horta, Faial., had a child, Maria Isabel in 1824. born Horta. I'm going to chase this up.
Hopefully they had more children.
Thinking here is that the only names John had for his mother, Louisa Constance, was because they
were her only names. As in Louisa CONSTANCIA. I've found CONSTANCA, with a squiggly thing under the C.
Using FamilySearch, I'm finding Jose equates to Joseph, Joao doesn't seem to equate to anything, but I'm not getting a John in any Portuguese islands or mainland. So am assuming Joao is John.
Also, comment from the sidelines,

Manuel CHRISTIAN, witness at marriage of John and Elizabeth, could be descended from Fletcher CHRISTIAN.

That bloke sure did get around.
Added; CHRISTIAN in the Azores is CRISTIANO/A