Seiko 7017-8000 speedtimer 5 Flyback Chronograph for $673 for sale from a Seller on Chrono24
1970 Seiko 5 Speedtimer 7017-8000 - YouTube
Seiko 7017-6020 Proof/Resist Speed-Timer from Feb 1971 – classicseiko
JC Seiko 7017-6020 JDM Speedtimer, bought on a cruise in the '70s - YouTube
SOLD ) SEIKO Speed-Timer 5 SPORTS rare waterproof chronograph Ref. 7017.6040 - matt black dial with internal bezel at 60 - complete with rare original bracelet - La Casa dell'Orologio