attic door hinge

One of the hinges on my attic door got bent all out of sorts. I tried straightening it in place but that was impossible so I took it off by force to either repair it or replace it.
With the help of a vise, a hammer, and a Crescent wrench I have managed to get it almost new. However when removing the hinge, the pin that holds the elbow to the attic entrance and adds support snapped off. I have removed the plate that held the pin and will have to put it back when I can replace the pin with something else. The plate is 3 inches square with 4 mounting holes. The center is raised with a hole in the middle where the pin was welded or riveted.
Whatever I use to replace it must be flat-headed and possibly smooth-shanked for the hinge elbow to ride on. I'm thinking of using a flat-headed screw with a nylon locknut underneath to keep it secure. Maybe using a normal nut on the head side to keep it in place and extended a certain amount and a metal hollow spacer that the screw would go through.
I don't know if I have explained it clearly. Hopefully others may have some suggestions also. Lowes doesn't carry the hinge and they want me to look through a catalog so they could possibly order a replacement through the manufacturer.
No matter what happens someone will find a way to take it too seriously.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.