Help to ID Jon Boat Accessory Channel

[MelLandry]

Hi everyone.

I'd like to find hardware to fit in my Jon boat accessory channel, but I don't know how identify it. Can anyone tell me how to search for the proper hardware to mount accessories to the channel in the picture?

Thank you,

Mel

 

[airshot]

Cant say I have saw that one before.....good luck.

 

[LDUBS]

Same here, that is very odd. Seems they went to a lot of trouble to make that shape. There must be a reason.