I inherited a watch that I would Never sell . Regardless I am trying to learn as much as possible about it.including a rough or accurate manufacture date. Can anyone help me with this Please. I`m very interested if anyone can give me any detailed information based on each number of the 7 digit Case Serial number. I would be very grateful for as much information possible Thank You.My Vintage Eterna-Matic Case serial number is # 3611314....Thanks Again. Details I know are that it says on its Dial face: ETERNA MATIC BIRKS CHALLENGER. I believe the watch case is stainless steel ? the Band appears to be stainless steel and stamped several times on the inside with FIXO-FLEX. The Dial is white with Gold Numbers 2 4 6 8 10 and 12. the other number positions are marked with Gold Dots. Also with smaller dots on the outside seconds ring. Second positions are not numbered but marked with short black lines. The watch hands are gold the watch Hand style is Alpha/Lance. I`m sure the watch is all original except maybe the steel FIXO-FLEX strap or watch band. I have not seen another watch with this exact same Dial as well as the Second Hand being Red etc.? The Second hand is Red and its shape or style is a long thin stick with a short spade tail pass the watch center. I haven`t measured the watch or had the screw in back removed yet.for more numbers etc.The movement is Automatic self winding . The Dial face and watch stem are both marked with the five ball bearing symbol . I have just joined this forum and have no idea how to add watch photos or properly use this forum sorry. Lol incase I cant find this message or read responses my email is firstname.lastname@example.org. Any help and information would be much appreciated Thank You Sincerely Ken.