Used scotch brite wheel on grinder to "break" the hard edges on both HS-609PP bars. Finished polishing both pieces, including previously noted 'blemish'. Rounded the ends of both HS-609PP and test fit the bars into the HS-603PP rear spar channels, making minor adjustments with the scotch brite wheel so that the bars would fit flush into the spar channels. Clecoe'd and #30 drilled all holes in the rear spar assembly. #21 drilled 8th hole from either end for the HS-708.