This was my grandfather's seiko chronograph "Jumbo" [6138-3002]. Still working fine after about 50 years. : r/Seiko
Seiko 'Jumbo' chronograph automatic stainless steel gentleman's wristwatch, reference no. 6138-3002, black dial with baton markers, minute markers, day/date apertures, subsidiary thirty minute and hour recording dials at the twelve and six
Seiko Jumbo (6138-3005) Price Guide & Market Data | WatchCharts
Seiko Chronograph Jumbo 6138 3002 de vânzare pentru 3.034 lei de la un Vânzator privat de pe Chrono24