Bed rail repair

I am trying to replace a bed rail for a friend. Upon looking at the damage I see they just used plywood. The layers of plywood just ripped apart.

Rather that just gluing and screwing it back together I decided I should just make a new piece out of solid wood. My problem is with the existing hardware. The exsisting hardware is bed rail hooks. They require a 3/32’’ kerf which is 3 – 1/2’’ high X 1 – 1/8’’ deep on the bed rail. I am not sure of the best way to cut this. My first thought is to try a slot cutting bit in the router. Before I try any thing I wanted to ask someone who knows what they are doing. Rockler sells this type of hanger but only recommends them for replacement only.

What do you think? Would I be better off buying different type of hanger? Thanks for any help.