On the 13th of September, 1660, Henry Stuart, Duke of Gloucester, the youngest son of Charles I of England and Henrietta Maria, died at the age of twenty of smallpox. After Charles II's death, people thought Henry might have been a better, Protestant, choice instead of James II or James Scott, Duke of Monmouth. Would the Exclusion Crisis have gone differently if Henry Stuart survived? I'm guessing that parliament might try to bypass James, Duke of York, to place him on the throne instead. Henry was described a staunch Protestant, so in terms of who he might marry, I've come up with a few candidates:
Elizabeth Charlotte, Countess of Holzappel (https://en.wikipedia.org/wiki/Elisabeth_Charlotte,_Countess_of_Holzappel)
Princess Anna Sophie of Denmark (https://en.wikipedia.org/wiki/Princess_Anna_Sophie_of_Denmark)
Christine of Baden-Durlach (https://en.wikipedia.org/wiki/Christine_of_Baden-Durlach)
Louise Elizabeth of Courland (https://en.wikipedia.org/wiki/Louise_Elisabeth_of_Courland)
Elizabeth Charlotte of Anhalt-Harzgerode (https://en.wikipedia.org/wiki/Elisabeth_Charlotte_of_Anhalt-Harzgerode)
Elizabeth Charlotte, Countess of Holzappel (https://en.wikipedia.org/wiki/Elisabeth_Charlotte,_Countess_of_Holzappel)
Princess Anna Sophie of Denmark (https://en.wikipedia.org/wiki/Princess_Anna_Sophie_of_Denmark)
Christine of Baden-Durlach (https://en.wikipedia.org/wiki/Christine_of_Baden-Durlach)
Louise Elizabeth of Courland (https://en.wikipedia.org/wiki/Louise_Elisabeth_of_Courland)
Elizabeth Charlotte of Anhalt-Harzgerode (https://en.wikipedia.org/wiki/Elisabeth_Charlotte_of_Anhalt-Harzgerode)