Originally Posted by Cory
The Duke Franz of Bavaria is the Catholic Heir to the Throne of Scotland.
He is more than that if we only count relations: he is the senior line heir as the senior line was deposed in favour of the (senior) protestant line. But it is not clear if the English and Scottish princess he is descended of (Henrietta Ann) has not rightfully given up her rights to the Brtish thrones on her marriage. For if she had a son instead of only two daughters, this son would have been the Head of the Orleans-line of Bourbons, so very close to the French throne. I personally doubt the parliaments of England and Scotland would have accepted a marriage so close to the kingship of France without enforcing a forfeit of her inheritance rights (which was quite custumary at that time when princesses from houses who had a female inheritance possibility married).
So I'm not convinced at the moment that this isn't a reality.
Then we come to Elizabeth of Bohemia, daughter of James I./VI. If she forfeited her rights, too, then there is no other claimant than the currant queen (for her right goes back to an Act of parliament accepting her ancestoress Elizabteh' right to the succession for her descendants).
If we believe Elizabeth did never give up her claims, then her first son would have been her heir. He left two children from his first and official marriage: a childless son and a daughter who married the widower of her cousin Henrietta Ann and bore him a son. Thus the Head of the House of Orleans would be next. But the duchess of Orleans herself gave up her rights to her inheritance (which was revoked by France at a later moment, but still..) If her line is out, the children of the second marriage of the Prince-Elector might have a claim. This marriage was considered by German Law as a marriage to the left hand, so that the children could not inherit the Palatinate. - a fact which the British don't see. IMHO they could well have inherited a de jure right to the thrones of Scotland and England.
Then the line according to the British traditions of succession goes via Lady Frederica Schomburg to Charles Pelham, the 8th (and current) Earl of Yarborough. So why not ask him to become king of Scotland according to his senior descent from Elizabeth Stuart?