There is the slightest suggestion of a seam at the very top of the body but only in the smooth area next to the aluminum(?) ring. I can feel it when I slide my fingers across it but doubt it would even show up in a picture.
Looking inside nothing like a seam appears except the circumferential seam.
On the inside of the lenses, there is what seems to be assembly marks at the top center, they appear to be white squares about 1/16 or 3/32 inch sides and are halfway between the edges of the N and the T. As best as I can tell, they are aligned with the slight irregularities discussed in the first sentence.
I have not removed the lenses from the body. The ends of the rings are secured with a screw and what resembles the "post" part of a post-and-screw fastener. They look weathered, so I am hesitant to try separating things.
