I made the stiffener for the bottom of the firewall recess and match drilled it to the firewall.
Next up was the brake bracket.
The firewall recess is also made of stainless steel. Everything fit fine except for the top two holes. The 1/8" hole was off by a half of a hole on both sides, and the 3/32" hole below it was almost as bad. Every other hole was spot on. Because of the bends, there was absolutely no shifting of the holes (well maybe if I had taken a hammer to the metal, but I didn't want to do that). I looked it up online and it turns out that this is a very well known issue. The holes are either drilled slightly off, or the bend is wrong. I found comments about this going back decades, so evidently Van's doesn't think it's worth fixing. I tried to line things up as best as I could, but in the end I elongated those couple of holes pretty bad. I'll have to see if it's a problem down the road when I rivet the recess in. That'll be a long time though - you leave it out to allow for a nice big hole in the firewall to ease installing things.
The last piece for the firewall is a fuel pump doubler (for the auxiliary pump). I triple checked the spiderweb of measurements on the plans, cut it out and drilled the holes.
I didn't realize how easy it is to drill through aluminum until it was time to drill through the stainless! I clamped the doubler in place and used the holes to drill the firewall. It's a bit slow with a lot of messy lubricant.
