Today i drilled and clecoed the floor and firewall stiffener square tubes secure to their respective location. I then positioned the stiffener bracket angle between the floor and the firewall stiffeners. There is also an angle bracket that connects the upper cross tie to the firewall stiffener.The last gusset was between the floor stiffener and the tunnel assembly wall.
I was then able to position the 12.5 inch half hinges along the bottom of the firewall 3/32' from the bottom and drilled through the stainless steel firewall. That material is very hard to drill through compared to the aluminium. Oil requried to lubricate and cool the bit.
I also attached the upper firewall assembly to the firewalllower sectionfrom the pre-positioned holes. the window strap piece required some trimming as laid outin the plans to ensure clearance from the longerons upper both left and right. It then also needed some trimming around the corners of the firewall flaps to fit the angle curvature. All in all a good fit all around.
I am now ready to upsize the holes and do the countersink drilling for certain fasteners.