Hi Dave: I am happy that you read my response with such enthusiasm . I use the standard halyard shackle & ring that comes with the boat for the top of the rigid extension...the shackle pin attaches to the hole in the extention(when you use the regular sail for the boat it is set up the same way ) & the ring is attached to the halyard line & fastens to the mast stop when you hoist the sail ! For the lower end of the extension ,the side that attaches to the sail,
I use a large standard stamped halyard shackle(with a captive pin to prevent loss of pin)the open end of the shackle first goes through the mainsail grommet & the pin locks through the hole on the extension. There is No slop. if you need further explanation or picks contact me: Billsails@hotmail.com give me your home address & I will send you a simple diagram ...If you sail a P-19 it will definately work ! Bill