Last step in the longeron bending process is to drill the aft canopy deck to the bend on the longeron. The aft canopy deck is an aluminum formed part that sits on top of the longeron angle and serves as platform for the canopy to rest upon.

As with all aluminum parts, the first step is to break and deburr the edges.

The af canopy deck starts where the bend down starts on the longeron angle and has to overhang the longeron slightly, just enough to be flush with the side skin.
To facilitate the mating process, you attached a stock piece of .032 sheet to the longeron and tape it on with some duct tape (or lots of clamps)

Mark a center line on the horizontal face of the longeron. This will be a double check for the position of the aft longeron deck.

Clamp the aft canopy deck on te longeron and check the alignment. You can still bend and stretch a little as you go while drilling but don't expect miracles.

Best is to be as close as possible at this point and then make smaller adjustments

 Started drilling from the front to the back putting in clecoes as you go. Continuously verify alignment.
If your aft canopy overhangs slightly over the simulated -side skin, no worries, you can still use the deburr wheel to adjust that later but make sure you are not short. 

Right longeron drilling completed.

Another view from the back.

See how nice the aft canopy deck mates over that side skin.

Then did the same for the left longeron but the process is exactly the same and I didn't bother to take any more pictures. It came out just as nice.