This may work...
Go to the boneyard and pull the hatchback latch assembly from a VW Rabbit.
While you are there, also get the hood latch assembly, complete with inside cable release if it has one.
Either assembly is common and cheap, matter of fact the rod suppliers usually have the Rabbit hood latch available for both hood and trunk use. It consists of a single spring-loaded pin and a simple latch mechanism that the pin indexes into.
If you go with the trunk latch assembly, you can raise the lid a bit after popping the latch with a couple common door poppers, they are just a spring-loaded pin assembly, and lift the lid about an inch or so. Alternately you could get a spring from a hardware store that has one end wound tighter, and use a bolt/washer to retain it to the lid or the trunk lip. The free end of the spring can just butt against the panel, or you can make a simple wear plate from a scrap of stainless sheet.