aghadowey,
Thank you for your perserverence. Sadly I do not have the marriage certificate, or even the date of the marriage, although I do have Isabella's parents' names: Rev John Vignoles Brabazon (7 April 1811-1899) and Mary Jefferson (1815-24 May 1855), and Rev John's parents: William Philip Brabazon (28 Oct 1783-13 Dec 1854) and Letitia Vignoles (12 July 1786-20 Dec 1859). But the family has nothing of Henry Elliott junior's parentage apart from what I have given.
The LDS Pilot site you listed has a reference to the correct Henry Elliott (junior) at Film No 101598 Vol 2 Page 555, DFN 4200680, Image 00495. Unfortunately I don't know how to take that further to see what it contains.
Terry