Hi! My name is ***** ***** I would be happy to help with your Van Briggle vase.
That's great that you have the original purchase documentation -quite a rarity.
Could you very kindly attach a photo of the vase and one of the mark on the bottom.
Also, is the hairline crack extending from the rim or located around the base?
PS. Once you have the photos in your computer (if you are using a smart phone camera, just email them to yourself) it's then a simple matter to attach them. Just click on the paperclip icon, located above the text box where you are typing to me. If there's no paperclip, click on the "Add files" tab.
If you get stuck go here for help.