Based on this image from the Ames catalog, it appears the lever arm on my latch is bent:
Not sure how that would affect the safety release but I guess I'll try to straighten it out.
The gap between the actuating pawl and the safety lever is narrower on this Ames image than on mine.
I might think about buying a repro but Ames says theirs is not like the image but is bright zinc plated. The ones like that I see advertised online don't look anywhere near the quality of the original nor the image Ames shows so I'm going to keep trying to get mine working.