An absolutely wonderful Ollivander, and a marvelous story. I almost feel like you filled in backstory for canon, on how Snape obtained parts of his well-rounded education. He was never one to turn down knowledge!
I'm impressed with how smoothly you were able to make us believe a pairing between these two of such disparate ages and temperament could work. I loved the calming effect Ollivander had on Severus--a character who's ill-temper is normally at the forefront of any story which includes him. And what a wonderful explanation for where Snape laid over while his name was cleared. All the details fit so well.
Thanks for taking the time to explore such a unique pairing! I look forward to reading more of your work after the reveal!