Take Pictures
The North loft in Seattle can take a picture of the sail and, with their computer program, determine how inaccurate the same might be. I believe they like a digital picture. While it's true that a loft person can come out to your boat it does take time on their part. Suggest first taking a picture looking up the sail trying to get as much in as possible. Oh, they also like draft stripes in the picture so if your sail don't have these then this may not be the best solution - talk to them about it. Also, they can 'get an idea' of the shape by stretching the sail out in the loft but this isn't as good as a visit to the boat or a picture.Your use if the cunningham is good. Can you get a full hoist with the main halyard? It's possible the tapered part of the halyard will make it difficult to get a full hoist as it can jamb into the mast exit hole. If this is the case there is probably chafe on the line.