Colonial paper money was about ¾ to ½ British sterling value, so coins were worth 1⅓ to 2 times their face value in the colonies.

Tables published in 1759 (during the French and Indian War) below, and 1786 (after the War of Independence) show that a Spanish dollar was worth 8 NY shillings, or 7s/6d in Philadelphia instead of the official British exchange rate of 4s/6d (not shown below because foreign silver coins were not legal tender in England.)

More proof.  Although a British shilling was about ¼ of a dollar in silver, the value "One Eighth of a Dollar" is clearly printed on this 1776 Colonial New York one shilling note.

Old Stone Fort Museum collection