Hull separation from top mold repair

Basically the two molds are separating from where the rub rail covers. it appear that prior owners have attempted to repair this damage with caulk or glue. It obviously didn't work all that well. I have removed the rub rail around the whole boat. The only actual way i think i can repair this is with a pop/rivit, screw or nut and bolt. I plan to push it in and apply some type of glue/caulk when doing this as well.

any suggestions on what to do?

I also plan on repainting the boat from the rub rail down. anyone have any suggestions on what to use or how to do it?

 

Pic one of me pushing the separation in

 

Without rub rail. I actually really like the look without the old 1980s bulky rail. Anybody have any suggestions that would work for me in a white rail? I can't believe how much it costs to replace by the way.

 

Without rail

 

You could grind things down and bond the deck cap to the hull, making a seamless transition.