Before you can mount the canopy frame to the deck, you need to make the attach point for the sliding block on the end of the frame. This is a slotted  UHWW plastic block  that slides over a rail on the top fuselage skin.
First the plans have you drill 2 holes on each side of the plastic block for the AN3 bolt. Carefully measured and drilled 2 pilot holes, then up-drilled to #12. You also have to trim a bit from the bottom of the block for less friction. I decided to first install on the plane and then evaluate how much i should trim.

Next, You hold the plastic block on the end of the canopy frame and check for clearence on rotating action of the block on the canopy frame attach tab.

 Then drilled the #12 hole through the frame tab.

Then it's time to make the slider rail. Tis consists of a long squared bar and a long strip of aluminum sheet. You have to bend both to the exact angle as shown on the plans.

Fortunatly, Vans made a 1:1 template drawing of this on the plans so you can easily match it against that. Having that angle right is quite crucial to good functioning of the canopy.

 Both nest together and the strip has a second bend near the end.

The hole locations are indicated on the plans. It's a bit of a puzzle to find the correct locations at first. Some of them are rivetted to keep the 2 pieces together. Others are holes for screws which will attach the rails to the top of the fuselage skin. At this point, you only want to drill the holes for the rivets that attach the two parts together. The screw locations will vary slightly depending on how you install the slider rail on the top skin so don't drill them now yet.

Some initial test fitting.

Time to drill the #40 holes through C-763 and C-762. Deburr, countersink and dimple the parts and all will be ready for rivetting.