This black distinctive football-shaped flip-up door latch was used on hatches and inspection ports for many years. The original manufacturer went under, but we found a source for them!
The football shape was unique. If the twist latch in your hatches or ports look like this, then this is the one you need. This one is black (off-white pictured), but a bright white version was also used. Complete kit includes both sides of the latch, spring, O rings and assembly instructions.
Dimensions: Latch handle is 2" long from point to point Round base of paddle on the inside is 1-1/6" diameter Paddle is 9/16" wide