The Day Sailer I as originally set up has the mainsheet attached to end of the boom, then goes down to a block on the deck in the stern, over to a block on the other side, then up to a block on the boom, along the boom to a block at mid boom and then down to a block on the end of the centerboard trunk which is also where the cam cleat is located. The Day Sailer II (like mine) had the the mid boom arrangement with the fiddle blocks and the cam cleat end on the end of the centerboard trunk. As I recall, the main sheet length for the DS1 is 48' for use with the original configuration. The DS2 uses about 35' for the mid boom configuration. The specs call for 5/16" mainsheet line, but I went with 3/8" when I replaced mine.
Under the technical section of the Day Sailer forum I think there is a copy of the owners manual.
John