Looking at your pieces I do think they were intended for a Double Wedding Ring quilt. If possible I would be looking for the rotary cutting plastic templates for DWR. If they are the right size I would use the already pieced sections and recut them with the plastic templates to size (I have seen them but it's been a while) You could draw up the pattern close to the size but a little smaller so you could neaten the original pieces before piecing or find a good pattern and bring it to a copier and enlarge or reduce the pattern to match the pieces. Good luck!