Help identify 35 yr old panels

I have a shop that was built in 1979 with a steel roof. I have never seen panels with this particular pattern...the ribs are 3/4" high, and 12" apart. The attic has 4 fiberglass skylights, and one of the fiberglass panels was damaged by wind/ice this past winter. The builder was kind enough to leave a spare metal panel in the rafters, so I will be able to make a repair this time. My concern is that if another skylight fails, I will not be able to find additional steel panels. I have checked with local hardware stores and a few roofers...no one has anything compatible. Is anyone aware of a compatible pattern?