Valbor, I have a Duncan Hudson Se5a and I have corresponded with him about his method for simulating the stitching on the side body panels.. Here is what he said in essence. He uses small eyelets and a soldering tip.. He lays out the side panel and folds it over itself making it double thick where the eyelets are to be positioned.. then the eyelet positions are marked. Using a small soldering iron with a blunt tip push it through the material making a hole.. The eyelet is inserted throught the hole and peened on the back side to fix it to the fabric... The top and side panels are made and then applied with excess material so they can be positioned properly and trimmed. The thread that connects the two panels is woven throught the eyelets in a scale manner per your pictures and documentation.. The full scale SE5a uses eyelets which are rather small but noticable. The AF Museum at Dayton has one hanging it its collection if you get a chance to visit..
BTW.. what colors have you chosen for your plane?? Regards BobH.