For sale is an Seiko 5 6309-5360. I purchased this watch a few months ago and have only worn it once. The dealer I purchased from had it restored and serviced. According to it's serial number, the watch seems to be from 1980.
Model : Seiko 5 6309-5360
Year Of Manufacture : 1980 (est.)
Movement : Automatic
Case Material : Stainless Steel
Case Measurement Excluding Crown : 35mm
Crystal : Acrylic
Band Type : New Leather Band
Band Length : 22cm including watch
Special Features : Date and Day Function
Condition : Great (restored)Asking for $450, inclusive of worldwide shipping. Payment via wire transfer, Paypal + 3%, Venmo, Zelle.