[the picker]

C19 is from the minus of the battery to the GND, C21....no good way to describe but one end is at the top lug of the volume pot (if you face the rear of the pot and the lugs look down then the leftmost lug, if the lugs look up, then it is the right one) , and the other C21 pin goes between the two resistors on the sch.

here is a pic of the battery the red is positive lead and green negative correct or not