You may feel that picture 3 raises the question of where to look for historical maps of Ireland. Going to the NLS as a reflex action meets with discouragement - no Irish maps sets in the list, nor places in the gazetteer. And yet, they do have quite a lot of
OS▸ maps for Ireland, including what looks to be a nearly complete set of 6" maps listed as 1829-1969. In most cases they will be from later to earlier than that; for Rosslare the three on offer are the 1840 survey and revisions of 1903 and 1943.
There's a trick to getting to them:
start with the search but ignore the gazetteer and list of map series, navigate on the map to where you want. Click on that place, and select map series from the list on a trial and error basis. If there are any maps you'll see their outlines, if not not. The OS Six-Inch, 1820s-1960s looks the most useful, even though internally they call it OS Six-inch Ireland, 1829-1969. At least, that does work - there may be other, and better, tricks too.
Anyway, that 1903 map shows the "railway and pier in course of construction", with its end not drawn. The turntable is in the place seen on the picture. The 1843 map shows that moved elsewhere, but buildings on the pier not seen in the picture - a goods shed and station. That suggests the picture was taken around 1903, or a little after.