"What Is This Silver Metal Thing With Narrow Bridge And Spoon Like End?"

Answer: "Ear cleaners, use them to scoop wax more common in eastern countries. Might be confused for a drug utensil by American police as they imagine people snorting the tiniest cocaine hit ever."
Pretty sure you are wrong.... the black/blue pages in those are thin. photo looks more like an album.
Better... er... what? That would depend on the specific function of the slide rule. I used these in an engineering drawing office early 70's
#56... That is what is left after removing a metal screen that was painted at one time
came with firearm accesories... Probably a wick for old gun.
But the two things can look more or less identical.