Servicing a Seiko 6138-3000 Jumbo Chronograph – ClockSavant
Seiko 6138-3002 'Jumbo' Chrono - opknappen of niet? - Vintage Horlogeforum - Horlogeforum.nl - het forum voor liefhebbers van horloges
Thomas' Timepieces - Seiko 6138-3000 and 6138-3002, both models often referred to as the Seiko Jumbo. The Seiko 6138 was arguably the world's first automatic chronograph (Zenith/Movado El Primo also claimed to