Hello Gary, Thank you for sending in this wrist chronograph to mearto.com for an appraisal. I shall try to help you with this today. TITLE: Aviator/Navigator, vintage, stainless steel, water resistant, manually wound wristwatch with dual round button chronograph, dual registers and tachometer scale, “Mono-Rattrapante” chronograph (the second version), Ref. 5347 (no telemeter present), case No.‘4963’(found on back of lug @11), made by Bovet Freres & Cie, Fleurier, Switzerland, circa 1940’s-1950’s. {Bovet Freres & Cie had factory in Fleurier with offices eventually in London, Geneva and New York City by the mid-20th century.} DESCRIPTION: Case: The 5347 was listed as 35, 37- or 39-mm diameter (size was not provided), round, two leaf, polished and brushed stainless steel case with, canted polished bezel, two round chronograph pushers, harp shaped lugs, steel back cover marked, ‘Impermeable, stainless steel, 5347 (model no.), 4693 (case no.)’. T No military markings are seen. {Two versions of this wristwatch exist: - the first, features a round, flat push-piece at 2 and an olive shaped push-piece at 4. - the second version has either a square or a round waterproof push-piece at 2 and at 4. Yours appears to be the second version} Dial: Black dial with painted radiumed Arabic hour numerals, railroad track with bar minutes/seconds divided into fifths of a second, with a tachymeter on the periphery with a base of 1000. There are two subsidiary dials: continuous seconds @9 and 30-minute register @3 dials. There are Skeletonized pointy baton white radiumed hands. The dial is signed in white script “Bovet” with an underlined flourish. Movement: Not shown but should be the 14 1/2"' rhodiumed, 17 jewels, lever escapement, monometallic balance, self-compensating Breguet balance-spring and an index regulator. CONDITION: Case – Good with spotty areas of silver oxidation on the back cover, the lugs, around the barrel as well. Dial – Very good with nice darkened patina to the numerals and the hands from age. I cannot see the dial is high resolution but there are markings or streaks in the lower dial which is difficult for me to know what that represents. Movement – Not seen but assumed to be as described, original to this case, genuine and functional. Overall, my impression is that this was not used during the war as military issue since it bears none of the expected USA air force or military markings. (These are marking I have become familiar with over time by just doing many watches.) HISTORY: It was in 1936 that Bovet created and patented a "mono-rattrapante" chronograph system that acted similarly to a split-seconds mechanism. The mechanism of the chronograph is started by the push button at 2 o'clock, while the push button at 4 would stop it and when released allowed the time to catch up to the actual time. After Jacques Ullmann went out of business in 1932, the Bovet name was acquired by Albert and Jean Bovet, who were successful watch makers and registered several patents for chronographs, such as the mono rattrapante—a device that would pause the second hand for a reading while the mechanism continued to run. The company Favre-Leuba purchased the name and manufacturing facilities from the Bovet brothers in 1948. The "Mono-rattrapante" chronograph wristwatch, is equipped with the device elaborated by Bovet on the Valjoux calibre 84. This particular wristwatch features the three normal functions of any chronograph, activated through the push-piece at 2, enabling the chronograph hand to: start - stop - return to zero. In addition, there are two further functions activated through the push-piece at 4: 1 - by depressing the push-piece, the single chronograph hand stops. 2 - by releasing the push-piece, within a maximum time of 60 seconds, the hand jumps forward, catching-up the seconds elapsed in the meantime. Two versions of this wristwatch exist: - the first, features a round, flat push-piece at 2 and an olive shaped push-piece at 4. - the second version has either a square or a round waterproof push-piece at 2 and at 4. (Similar watches are published in Chronograph Wristwatches, To Stop time, by Gerd - R. Lang and Reinhard Meis, pp. 21, 50-51, 180-181.) COMPARABLES: ~https://catalog.antiquorum.swiss/en/lots/lot-102-423?browse_all=1&page=2&q=Bovet+chronograph (normally I would not show comparables from the 1990’s but this, I believe is your type of watch) ~https://webcache.googleusercontent.com/search?q=cache:AJwuwJypf_AJ:https://www.fellows.co.uk/1737-lot-449-BOVET-a-gentleman-s-stainless-steel-Mono-Rattrapante-chronograph-wrist-watch%3Farr%3D0%26auction_id%3D9398%26box_filter%3D0%26department_id%3D%26exclude_keyword%3D%26export_issue%3D0%26high_estimate%3D0%26image_filter%3D0%26keyword%3D449%26list_type%3D%26lots_per_page%3D%26low_estimate%3D0%26page_no%3D0%26paper_filter%3D0%26search_type%3D%26sort_by%3D%26view%3Dlot_detail%26year%3D+&cd=3&hl=en&ct=clnk&gl=us (this is the first version with telemeter and tachometer, sold in an English auction for 3317 GB Pounds) ~https://www.barnebys.com/realized-prices/lot/a-very-attractive-and-rare-stainless-steel-mono-rattrapante-chronograph-dvP8S1EYc4 (in excellent, near mint condition this example sold in 2018 for $30,000 with dial that is tropical and has aged to a brown.) ~https://www.barnebys.com/realized-prices/lot/bovet-a-very-attractive-and-rare-stainless-steel-mono-rattrapante-BldPNemXPh (also in superb condition with a tropical colored dial, sold for $18000 in 2018) https://www.barnebys.com/realized-prices/lot/bovet-chronographe-mono-rattrapante-n-5347-xxxx-vers-1940-ytT5cyy8m (with black dial and little aging to the numerals this example sold in 2016 for $4400.) ~https://www.liveauctioneers.com/item/57581386_bovet-mono-rattrappante-swiss (sold in 2017 for 5500 Euros) ~https://www.liveauctioneers.com/item/66784032_bovet-monorattrapante-chronograph-in-steel-and (With heavy wear to the case this model one with telemeter and tachymeter sold in 2019 for $1000.) PRICING: So, you can see that the range of prices is quite wide, a great deal depending on the condition of the piece. Your example is lacking the original band but the watch itself is in good condition even considering the oxidation speckling to the case. It is not considered in the ‘very good’ nor ‘excellent’ category. The numerals have signs of age as well as do the hands. My impression is that the fair market value of your uncle’s watch in today's marketplace would place it in the $5250-$6500 range. I do hope that my description matches up with your knowledge of this fine timepiece. Thank you for choosing mearto.com for the appraisal. My best, David
