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Vintage SEIKO 6138-7000 Slide Rule Chronograph Automatic Cal 6138B – 44 mm – St. John's Institute (Hua Ming)
Slide Rule Calculator ' - Seiko Ufo Ref'7000 - Automatic Chronograph Cal'6138 Japan - Good Vintage Condition - Good Working - Circa Juni… | Instagram
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Seiko 'Slide Rule' calculator, chronograph automatic stainless steel wristwatch, No. 6138-7000 - Jewellery, Watches, Silver & Coins
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BN SEIKO 5 SPORTS (Slide Rule Bezel), Mobile Phones & Gadgets, Wearables & Smart Watches on Carousell
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Seiko CALCULATOR SLIDE RULE Vintage automatic chronograph... for $2,705 for sale from a Trusted Seller on Chrono24
My Eastern Watch Collection: Seiko Prospex Sky Slide Rule Bezel SRPB61K1 Navitimer (similar to SRPB57 and SRPB59) - A Manual Computer with Limited Use, A Review (plus Video)
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