"It was at once exciting, overwhelming and intimidating,"director Shane Fitzgerald said.
"[And second] Where are they? The majority of his works are in private collections, and we don't know."
"When you paint for an exhibition, the paintings disappear off to the gallery, and if they're sold, you think, 'Well, I'm never going to see it again' … and you lose track of it,"he said.
"It is part of the excitement of curating a show of this scale."
"And so it becomes a bit of a chase,"Mr Fitzgerald said.
"We did look hard, far and wide for those works and sadly … there were about a dozen works that didn't make it into the exhibition, "he said.
"Seeing [them] again is amazing … they are like lost friends, it's like a bit of a reunion and it's terrific."