I finally got back to drilling of the firewall. I had taken a break from the main airframe and worked on a few smaller parts (brake pedals and seat components).
I spent the beginning of the day getting the firewall properly aligned with the forward edge of the fuselage. I had to grind away a little material on the left longeron to get everything to align properly. There’s a discrepancy in the manual in regards to the position of the firewall. Van’s provides 2 different positions that differ by 1/32 inch. Based on some internet research, it looks like this discrepancy doesn’t matter because any mismatch in spacing will be handled when the cowling gets trimmed.
I used a bunch of clamps to properly locate the firewall to the fuselage. This required a ton of minor adjustments and position checking.
I used several C-clamps to constraint the longeron against the steel angle.
Here are the rivets temporarily installed to align the skin to the longeron.
Van’s doesn’t tell you when to actually drill the bottom skin to the firewall, so I drilled half of the bottom skin holes to lock in the position. I’ll do the other bottom skin holes next time I go in. I drilled all the holes from the side skins to the firewall. 
This thing is looking really good!
