![Seiko - "Calculator" Slide Rule Huge Double Chronograph Cal.6138 - 6138-7000 - Men - 1970-1979 at auction | LOT-ART Seiko - "Calculator" Slide Rule Huge Double Chronograph Cal.6138 - 6138-7000 - Men - 1970-1979 at auction | LOT-ART](https://gcp-la8-storage-cdn.lot-art.com/public/upl/57/Seiko-Calculator-Slide-Rule-Huge-Double-Chronograph-Cal6138-6138-7000-Men-1970-1979_1599317820_3166.jpg)
Seiko - "Calculator" Slide Rule Huge Double Chronograph Cal.6138 - 6138-7000 - Men - 1970-1979 at auction | LOT-ART
![SEIKO CALCULATOR SLIDE RULE 1976 Vintage automatic chronograph watch Cal. 6138 Ref. 6138-7000 *** BEAUTIFUL *** Seiko Vintage watches - Watches83 SEIKO CALCULATOR SLIDE RULE 1976 Vintage automatic chronograph watch Cal. 6138 Ref. 6138-7000 *** BEAUTIFUL *** Seiko Vintage watches - Watches83](https://watches83.com/71026-thickbox_default/seiko-calculator-slide-rule-1976-vintage-automatic-chronograph-watch-cal-6138-ref-6138-7000-beautiful-.jpg)
SEIKO CALCULATOR SLIDE RULE 1976 Vintage automatic chronograph watch Cal. 6138 Ref. 6138-7000 *** BEAUTIFUL *** Seiko Vintage watches - Watches83
![Seiko - Seiko - "Slide Rule" Chronograph Automatic Watch -- 6138-7000 - Men - 1970-1979 at auction | LOT-ART Seiko - Seiko - "Slide Rule" Chronograph Automatic Watch -- 6138-7000 - Men - 1970-1979 at auction | LOT-ART](https://gcp-la8-storage-cdn.lot-art.com/public/upl/41/Seiko-Seiko-Slide-Rule-Chronograph-Automatic-Watch-6138-7000-Men-1970-1979_1588478253_1301.jpg)
Seiko - Seiko - "Slide Rule" Chronograph Automatic Watch -- 6138-7000 - Men - 1970-1979 at auction | LOT-ART
![Seiko Rare Calculator Slide Rule Vintage Automatic Chronograph... for $2,515 for sale from a Trusted Seller on Chrono24 Seiko Rare Calculator Slide Rule Vintage Automatic Chronograph... for $2,515 for sale from a Trusted Seller on Chrono24](https://cdn2.chrono24.com/images/uhren/25336892-jdasqxes2lu7duicfhgpqy86-ExtraLarge.jpg)