I finished off the two firewall penetrations by filling the leftover void with firewool material and clamping in place. (re: firewall penetration instructions) Not as easy as it looks.
I also used pro seal to seal off all the cable penetrations into the cockpit including: Throttle, mixture, carb heat, alternate air and the nose gear bolt access hole. This was a bit of a trick and very messy to get cleaned up. The better solution here is to use firewall pass through eyeball brackets, or similar, for each individual cable, which allows the subsequent removal of the cable without tearing through firewall sealant. That however would require specifying your own location to drill holes through the firewall because the holes specified in the plans are too close together for those. At the time of drilling the holes i didn't know enough deviate from the plans, so i went per plan.
