Turns out Vanderbilt Manhattan mansion was up for sale. Maybe clues?

https://www.dailymail.co.uk/news/article-6478851/Fire-rips-one-New-Yorks-Gilded-Age-mansions.html

https://nypost.com/2017/04/15/for-50m-you-can-own-the-last-of-manhattans-gilded-age-mansions/