Fitting cross bars to existing rails ARE cap

I recently got a used ARE cap that already has rails installed, but no crossbars. I haven't found crossbars that fit these rails and I'm not even sure what to call this type of rail set up to aid in my search. Appreciate any advice as to what these rails are called or what cross bars/feet would fit

 

Looks like a long gutter plate to me. Usually mounted more vertical I would guess. Prob any tower for a rain gutter would fit. Like a Yakima 1A.

 

Are those some DIY tracks? I thought most tracks have a C channel. I’m about to install some tracks onto my topper and I bought the rhino rack RTC tracks. Maybe replace them with Yakima, Thule, or Rhino tracks

 

Put new tracks in

 

that channel needs a thule gutter tower.
Load bars slide into the tower.
towers lock into channel at whatever position you want.
They come in regular height and extra tall.

 

387 is 8 inch clearance can hold 165 lb rating. I had them on an ARE cap back in the day.

 

Thanks for all the help. I think to reduce the hassle of finding a match and increase load capacity I will just get new rails and leave what's there.