Derick Gates SM2K #400 Brava
The hinge consists of a long pintle that is incorporated into the fiberglass along the forward edge of the platform and the gudgeons are two stainless steel eyes that are attached to stainless steel brackets that conform to the outer edge of the hull in the stern. These brackets are placed just above the rubber bumper on the stern. The ends of the pintles are capped with stainless steel eyes to prevent the pintles from slipping out of the gudgeons on the brackets. (See the new pictures I posted in the Photos section).
I assume that all pieces were custom made by the previous owner, and not available commercially.