thank you, I noticed you are using Blender to model and slice the models. an easy way to add pegs as I mentioned. First slice the model in one place. create a rectangular cube or cylinder as a peg or plug, you can then put this rectangle in the middle of the 2 parts. then use the tech in this video (https://www.youtube.com/watch?v=-qryNcBPHyE) to cut the rectangle out of both model parts. This way you don't have to eyeball it. Now when we print the model we need to print a peg to join the 2 parts. but if our printer isn't as good as yours we just need to mess with the plug to put the model together. Also, try to use the same peg for all locations so that it's easy to print. Again thank you for the quick turn around.