Hi Bass,
Two good sources of white apricots are The Arboreum Company and Bob Purvis Nursery.
Could it have been the Moniqui white apricot? That one is white with a blush. Spanish origin. But it seems to be the most reliably productive white cot.
http://www.arboreumco.com/store/products/moniqui
Or perhaps Lasgherdi Mashad of Iran? Ghostly white. Rich and juicy.
http://www.arboreumco.com/store/products/lasgerdi-mashhad
There are many other white cots out there: Sparks Mammoth; Canadian White Blenheim; Shalah; Sugar Pearls; etc etc…
Forum founder @scottfsmith knows a lot about white cots. He is trying to grow many of them. Perhaps he’ll chime in.
It’s hard to know what you had, Bass, and whether it is a known variety or something unique.