You might find this link useful
http://www.sacred-texts.com/tarot/faq.htm
From what I can gather from this is that the RWS and the PTK went in to the public domain in 2012.
US Games lost their right to enforce their copyright law in 1985, if you wish to claim a new copyright then it must be a have a substantial amount of original creative work added to it, then you have a copyright for your version only.
The only way I see US Games having a successful claim on copyright is if you use any of their decks or copy their card backs or card boxes.
Because their such a giant company and have the monopoly on selling RWS decks they will try to get you to buy a license fee from them to create your deck.
But in my opinion if they did take you to court for copyright infringement I don't think it would hold up in a court of law, as long as you have added your own creative addition to the original Line drawing from 1910, and created your own backs and box design for the deck.
To ease your mind you can also consult a copyright lawyer with whatever creation you come up with the original Line drawings.