Hi Michel, Sorry for misunderstanding. Do you mean the left side of the image, or the left side of the hull (to the right, in the image)?
Oh gosh. I'm going to plead ignorance there, sorry. It doesn't really make sense that it would be a 56, I agree, but it's also indistinct enough that I'm not sure it's really numbers? Then again, as I look at the Firefly pictures in a new book, the author is pulling stuff out of the images that I'm not capable of discerning, i.e. I'm certainly no expert!