About 8 years ago my wife and I laid armstrong laminate flooring in our home to get rid of the carpet. I am a pretty good carpenter BUT I had no idea how to navigate under the doors. I read and read and then learned that you had to under cut the door jamb to allow the laminate to go under it etc. All was going well until we laid the back bedroom that we are using for an office. I stopped the planks to short to be covered by a t-mold piece under the office door. I have some of the original heirloom pine (3pieces) and would like to add them to the CUT OFF ends to fill in to the location of the T-Mold. Do I cut out on the already laid pieces to receive the new short factory edge pieces tongue or just cut the tongue off and shim the pieces to flush and then glue ?