James,
Those records were in Fermanagh House, at the time they were filmed by LDS.
You are a brave man, visiting the record offices at this time of year!
[There are many visitors from abroad just now, intensely focussed on their research ...]
To maximise your herioc efforts you could visit the Linen Hall Library, to consult the newspaper indexes of BMD info.
[Top floor, ask for the book-form one that is held behind the desk - it goes in to the 20thC.]
Try to time your visit for late afternoon on a stifling wet day, just as the thrice-rejected folks who have queued all day hoping to get on the Belfast City Hall tour storm in, intent on venting their frustration ...
[The only record office I ever came out of, feeling like I needed immediate hospitalisation!]
Capt. Jock