Seiko 6139-6002: what parts are aftermarket and, more importantly, how can you tell? Didn't cost much and condition is obviously too good to be original, just keen to learn a little about
VINTAGE SEIKO 6139-6002 BACK CASE / BACK COVER FOR SPARE PARTS USE | eBay
Seiko 6309 6105 Pawl Lever | Seiko Parts | WatchMaterial
Vintage SEIKO 6139-8050 Speed-Timer Chronograph Automatic – FOR PARTS / REPAIRS – CROADCO Watches
Seiko 6139 6002 Pogue Pepsi Watch Case, Movement & Parts for Restoration (B86)
SEIKO 6139-6012 watch parts for spares | #1773131409