I don''t know if someone could run diamcal with the info. provided but did you see the stone in person? Let your eyes take care of the rest if possible.
Remember, you are buying the stone not the paper. I know how stressful this process can be but the stone looks good so far.
An ideal scope image is always helpful, if you can get one.
Maybe one of the experts could do diamcal for you. Giving you a thread bump-----
Trust me I know.... but the experts here wouldn''t let you buy a dog!
My advice is to evaluate the stone in person, see if your eyes like it then take it from there.