Hello,
Much of the information you have been referring to on Family Search has been provided by me and you'll see that I almost always provided a 'Source' with image along with the information I attach, and you'll see my username 'smacguf' where I do. I would be leery of accepting information you find on Family Search without 'Source' information provided, particularly by "Phyllis Hobbs_1'. I have had communication with Phyllis to request source information for many dates she has attached to this Olliffe family tree and her reply to me was "I don't know". That said, some of the dates are actually quite fitting, however I don't accept these until I see where they've come from, even if that happens to be family notes, such as old bible entries, notes on old photos etc..
The key to learning more about Robert Olliffe and Lydia Maria Seymour I believe will be within the Brinny Parish Transcripts, which are currently held in Dublin if I remember correctly. These transcripts are NOT available online unfortunately at this time.
George Olliffe and Thomasine Good are my 2nd great grandparents through my biological father, who was an Olliffe and I have been tracing this family since the early 2000's. I have much more, but speculative information regarding Olliffes (also Oliffe, Olive, Auliffe etc.) from areas surrounding Brinny, such as 'Little Silver' (Kilbrogan parish), Kilpatrick (Brinny), Clashanimud (Brinny) and Lissanisky (Knockavilly parish).
As mentioned in this thread there are a number of Olliffes found in the St. Finbarr's parish transcripts with dates that are also very fitting. Unfortunately there is little evidence to verify a connection. I've noted that there is a small part of St. Finbarr's parish that is separate from the main parish in Cork City and that is within close proximity to Brinny and Knockavilly parishes.
I'd love to hear from anyone researching this Olliffe family who wishes to collaborate, share or even debate findings.
Shawn