"They were meant to be together," says Mr Vellinga.
"Yes, they were very strongly bonded," replies Ms Groenenberg.
"He brought her to Holland in 1953, that was the year I was born. Because she had to learn the Dutch language, they thought it would be a good idea for her to take care of the little baby, me, and that is when our relationship first started."
Theo, a native of Holland, passed away in 2005 after battling Parkinson's. Koula continued to collect art up until her death in 2014.
Mrs Vellinga was a passionate supporter of local artists.
Elliot Mason lived a few hundred metres up the road from Koula.
"The first work of any substantial money that I ever sold, it was Koula who came through and picked it up. It was of Nga Tama Hineroa, which is the big flat top peak in the Kaimai's."
Mr Mason says Koula, a Cypriot, was deeply respected in Tauranga - her support was pivotal in getting his career started.
"She wasn't narrow-minded either, especially with what she collected. You can really see that reflected with what is here in the collection."
109 paintings were included in the auction collection. Tom and Anne-Marie say it's only a third of what the Vellinga's collected.
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