Covered sides of the 661 slide block with masking tape and marked for drilling. Drilled a 1/16” hole in one side of the block, installed on the canopy rail, looks ok. Drilled hole to 1/8” and then had a brain fade. While I had the block in a vice on the drill press table, decided to drill thru the previous hole and the opposite side at the same time. Hole came out about 1/16” too low. Put it together and seems to slide pretty well, but has slight bind. Will order another tomorrow-hopefully a WHITE one. Put the canopy frame on the rails—besides the tail sitting too high, appears to have some twist in the aft portion—probably other areas as well. Used a 2x4 to start working the tail down—going to take a good bit more bending—arrggg!