So the Helix 7 units do not have a cable connector available to plug your graphs in like the Helix 8's and up. I decided I would like to have one instead of constantly plugging and unplugging 3 cables every trip out on both graphs. I used Fusion 360 to do the design and printed with Pet G. Each Plug Dongle take 5 M3 x 16mm allen head screws to hold together. I test fitted with spare cables I had lying around, fits well. Will install on boat tomorrow and post pictures.
I have the files you would need to print your own, or have someone print for you just let me know and I could send. Whatever format you need.