I had an inspection on a 1957 house. The overhead service mast isn’t high enough to hold the drip loop to the minimum "18 height above the roof. My question is, is this 1957 house exempt from that rule?
From the 1956 NEC:
So I saw that NEC code as well, but my take on it was the code was talking about the service passing over a structure… This diagram is current code, has the minimum vertical clearance been reduced since 1956?
Of course there are so many out there more experienced then me but my opinion, Call it out for repair, I may have left it go if the metal roof was not even there, but I am also curious to see what the more knowledged say
I am thinking that metal roof was not there when the original installation was performed. Roof added later, and service not changed.
Who cares what was done in the past, especially in the 1950’s? It is what is…today & right now. What do you think the reasoning is behind the clearance?
Researching and studying codes and practices from the 50’s would be completely ludicrous, don’t you think?
IMO yes but I’m not an HI. I would be more concerned about the nearly 60 year wiring being near the end of it’s life cycle.
Old wiring? No problemo! Just GFCI everything and it’ll be good as new! Realtors will love you for not suggesting such a costly and dastardly thing like replacing the old wiring designed for 1950’s lifestyles. 
Except in this case it is SE conductors… nothing that GFCI can remedy.
As you say, it is what it is. Furthermore, it may have been okay when built. The metal roof part of building may have been added later, who knows maybe 20 years later.
Nothing one can do, may have been compliant when built. Identify as safety concern and move on.
So let me be blunt here. My concern is safety. No one wants a claim on their insurance due to an item not being called out correctly. How would you call this out? Call it out at as a safety concern and recommend it be corrected?
I would.
Thanks for the input guys.