Thanks for the photo. I don't have them on my boat.
In regard to making them or trying to fix the old ones, note that HDPE like Starboard does not glue well at all. Most assemblies you see made from HDPE use screws to hold pieces together.
There are some adhesives that supposedly will work, but I had no luck with them.
Perhaps other can comment as to whether they have the same holders. I am not sure they were factory since it seems like they block access to that deck plate.
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It may fit, you have to measure. It doesn't fold though.