Alpina Tropic Proof

Steel, high quality vintage watch from the late fifties. Manual movement, no. 787302/105. Caliber 598R . Last 3 digits in serial number is x865. Reference (between lugs) 7302. 34mm, ca 1960. “Vacuum” FB case (Francois Borgel). FB Cases were patented early stainless steel cases used by prestige watch brands like Patek Phillipe, Vacheron Constantin, Movado, Mido and Alpina.

“There is an inner cover or cuvette between the screw in case back and the movement carrier ring. This cover is deceptively similar to the inner dust cover found in watches with hinged backs and so it is often described as a dust cover, or sometimes more imaginatively as an anti-magnetic shield. It is neither of these!

The precision machined Decagonal screw back and lead gasket form an excellent waterproof seal; a separate inner dust cover is simply not needed. The material the cuvette is made from is not ferromagnetic, so it cannot be a magnetic shield. So what is the cuvette there for? It is there to hold the movement in place”.

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