ELG is the marking showing the rifle was test fired at the Belgian Proof House in Leige, Belgium. Unfortunately, there were thousands of these, and not enough information in your post to identify it.
Made in Belgium.
Belgian made @ turn of the century
The model number should be stamped on the barrel just above the trigger guard.
Yes. Why? Call me. 434-286-2496
This gun was made in 1924.
This is probably a replica revolver produced in Italy.
Plain barrel, solid rib, or ventilated rib? Condition? Plain barrel in 60% condition lists for $365. Vent rib in 100% is $1495. Manufactured in 1957.
10-100 usd
An octagon pyramid is more properly called an octagon-based pyramid. It is a 3-dimensional object whose base is an octagon. Attached to each side of the octagon are triangles whose bases are exactly the same lengths as the corresponding sides of the octagon. The "free" vertices of these triangles meet at a point, the apex, in a plane above the base.
It's been altered after it was minted. No extra value.
s diameter of the circle in the drawing above is the segment
The barrel is usually above the centerline of the gun. When fired, recoil pushes straight back from the line of the barrel, but that is offset above the centerline, and causes the gun to pivot.