If I was to guess I would place it sometime between 1965-1980. I can be wrong about this. Can you get a closer/clear picture of the tags? The tag might narrow the year.
You did a nice job. Now for the bad news. I do believe that isn’t a safe so much as a fire box being it is a sheet metal box with fire fill between the outer and inner sheet metal. Also the fire rate material is expired (back then it was only good for 12 years) on it so don’t count on it to protect against fire. My father had one just like it in the 1980s…. granted yours looks MUCH better! It would keep kids out… little kids.
BTW - are you using a wet paint or a powder coat?