A woman at the Newfound Rondezvous had the advanced Leidy lid set up. She had a string inside the cockpit that ran through the bulkhead. When she pulled it it pulled the bungee off a half hook underside the hatch cover (nearest the cockpit) Now the hatch is released. to grab it, she had a wooden round wheel (or ball) attached to string so that once pulled, the ball pulled up to the hatch cover , forcing it to pop up a half inch or so.

Here it is in English. A string runs through the bulkhead to the hatch cover. tied to the end of this string is another short piece of string about 6" long (attached in the center ... so now you have a (Y) with 3" of string on each end. One end attaches to the bungee and pulls it of a half loop under the lid. the other end has a ball the popps the lid up since the enty point of the (Y) shaped string runs through a loop right under the deck just in front of the hatch.

It was really ingenious. Simple if you saw it. Tough to describe. Hope I did it.