Silhouette-point, to aim. One can fine-tune elevation, by remembering how much of the top of the weapon to see, in the form of a shallow crescent. Seriously, the philosophy of the Seecamp pistol is to point the thing, and shoot.
There is not much metal, between the bore, and the top of the barrel. I would not want to cut into that part, and do not trust adhesives.
Again, the philosophy of the Seecamp pistol was first stated my the founder, Ludwig W. Seecamp, decades ago. He did not believe that such a pistol should have sights, for its real-world application.