Removed the remains of the steel reinforcement plate at the top of the rearwards entrance pillar.   Cut out the rotten wood which extended from the cantrail joint for about 12 inches down the pillar.  I used the router for this, leaving one good edge intact in order to enable me to get the correct profile on the finished repair.

Cut some new ash to replace this section, drilled and screwed it to the pillar using PVA to add strength and structural sealer to ensure no gap between the remaining pillar edge.  Drilled and pegged the repair using a pair of hardwood dowels.