@MarcRumble_1758526 I haven't figured it out yet but tonight and tomorrow I think I'm going to print some more. and superglue them with thick CA and then tack them together with some hot glue and/or try using clamps. I'm not gluing the sides together because I may try to extend them. Just the front and back. I hope this helps? Also using a soldering iron to melt a tack after gluing them. Arm n Hammer will set Super Glue instantly.
@MarcRumble_1758526 I just uploaded new files with pegs or plugs. I think this will be the final iteration for awhile. Sorry if you've wasted filament...