Conflict over Grandma's Collection

I am currently in a conflict with a cousin over the ownership of a collection of over three hundred dogs - ceramic, wooden, glass, etc. - that belonged to our grandmother. The cousin claims that the collection was "given" to her by her father (now deceased) and another aunt a few months after our grandmother's death in 1983. At that time, no one else was offered any of the collection. All these years, the rest of the family assumed that this cousin was merely "keeping" the collection together. Now, myself and other of my grandmother's heirs would like to have some of these dogs . . . and, in fact, in her will, my grandmother stated this to our one surviving aunt: "Ellen, the dog collection I'm leaving to you. Keep them intact if you wish, however, you can feel free to dispose of them as you wish." And "my personal things are to be taken care of by returning any things given to me back to the person who gave them, if they want them back." The aunt would like to see the dogs shared now, but the cousin claims she is the "rightful owner."

The question is this: does an oral action - that of the aunt telling the cousin 18 years ago that she could have/keep the collection - take precedence over our grandmother's will? Who is the rightful owner of this collection - the family, or the cousin who claims them all as hers?

Thank you for listening and for any advice you might have.

Depending on when the Will was made -- before or after the alleged gift -- and the specificity regarding the dogs, it would reflect your grandmother's perception as to whether there was a gift or just a holding.