The only way I could get the plexi to attach well to the forward canopy bow and windshield frame was to use a series of spacers across the center area of the canopy bow. Some of these are 3/16 inches. I'm assuming the supplied AACQ-4-4 rivets will not have the required grip length. I'm guessing I'll need somewhere around -6's and -8's. I haven't found these on the Van's web store and I've only located one supplier who will sell me a 100 pack of -6's for ~$35.00. Do you know of any source where I can get a handful of AACQ-4 rivets in the range -6 to -8? Is there an adequate substitution?