That's about average for pinning the seats and installing the transom.
Let's add as few steps to that:
-Gathering parts
-Padding Cabin Top
-securing boom out of the way
-Moving Hull to assembly location
-propping hull open
-pinning seats and installing transom
-installing bow piece, painter and lock cable
-rigging sling and launching dinghy
-installing motor and fuel can
-collecting and installing anchor and safety gear
-restablishing order on mother ship
Yeah, forty minutes is about right.
As for my missing arm, I specifically asked Bob not to tell any one.
Very cruel BB