I did not know if this question was best fitted here or in the Single Shot forum.

In 1888 Springfield Armory modified the 1884 trapdoor action with what they called a "Positive Cam" addition to the lock, to wedge it more tightly closed. Does anyone know where I can get technical drawings to enable me to replicate this mechanism?

Does anyone have a report of strength testing done with these model '88 Positive Cam actions in comparison to the standard model?

Thought about it, but decided this is properly to be in the Gunsmithing forum. I'll move it there for you.

If you could get ahold of Mike Venturino from rifle and handloader magazines, he would probably know, he seems to be the expert those old springfileds and sharps, etc

There are two places for the information you seek. Whether they will do the research for you is the question. First is the National Archives, and second is the library of the U.S. Army Ordnance Center and School, Aberdeen proving Grounds, MD. A Google search of these should give you contact information.