SOLD - 1973 Seiko Panda ref. 6138-8020 | Omega Forums
Seiko Rare Calculator Slide Rule Vintage Automatic Chronograph... for $2,504 for sale from a Trusted Seller on Chrono24
Seiko 6138 Yachtman AUTOMATIC CRONOGRAPH - Etsy
Sold at Auction: Seiko Calculator Automatic wristwatch chronographwith 30/60-minute counter, 12-hour counter, day of the week (German/English) and date,