Looking at replacing a metal roofing panel that was put on in 1917. it is a interlocking hidden fastner system. I don't think any of the normal vertical seam systems is what they are looking for but hidden fastner they do want. I don't have any pictures. They are not trying to match anyway. They would like somthing that goes with the old barn though. I'm in California. Any thoughts or info would be helpfull thank you
Google is your friend. Refine your search as you did deeper. Or make your own in your shop.