IMHO, cut the lug off, but keep the plate. If you don't have access to the "Recreating the American Longrifle" book, there should be a couple of tutorials on the various forums with instructions on how to make a single trigger, and how to locate the pivot pin. A properly located trigger will provide a nice, light, let off. The trigger set up you currently have, will be a bear to pull, even if the height of the bar is increased.
Watching the Kibler Colonial kit, assembly video will give you an idea of the proper location of the trigger pivot pin. It will also help to control the slop of the trigger by cutting a notch on the rear of the bottom of the trigger bar, to bottom out on the rear of the slot in the trigger plate. If I remember correctly, Jim Kibler explains the proper amount of trigger travel, and how much play the trigger should have, in relation to the sear bar and the top, rear, of the trigger plate.