Folding brass magnifying glass

This item is a pocket-sized, tri-fold magnifying glass constructed from a metallic material appearing to be brass, featuring a warm, unpolished patina with visible surface wear, minor scuffs, and darkening consistent with age and handling. The object consists of three interconnected square panels hinged together, allowing the device to fold flat or unfold for use. The top panel holds a circular glass lens. The middle panel features a circular aperture or cutout, and the bottom panel features a square aperture bordered by a dark, possibly painted or rubberized, frame. Visible directly stamped into the metal near the hinge of the bottom panel is the text reading 'MADE IN FRANCE'. The owner supplies additional unverified context stating that the item is a tri-fold brass magnifier made in France. The identification rests on the visible physical configuration of the folding metal panels and the legible stamp, though overall age, exact manufacturer, and authenticity remain unverified.

Based on what I can see in the provided image, this pocket-sized, tri-fold magnifying glass features a brass-like construction with a warm, unpolished patina, surface wear, and a visible stamp reading 'MADE IN FRANCE'. Per user submission: attributed to a vintage French tri-fold brass magnifier. I cannot verify from a photo whether the metal composition is solid brass or plated, nor can I determine the exact age or true manufacturing origin without physical handling. My evaluation assumes the owner's claim regarding its French origin and period is correct. Under that working assumption, items of this type typically trade in the $75 to $150 range within the vintage optical instruments market, driven by collector interest in portable scientific curiosities and travel accessories. However, visible surface scuffs and darkening impact the overall condition value. What would be needed to confirm authenticity and exact age includes in-person examination by a specialist, hallmark verification, and material testing. If physical inspection reveals the item to be a later reproduction, modern replica, or a generic copy rather than a period piece, the value would likely decrease significantly to the $20 to $40 range.