hi there
im not an expert. but i did saw this seiko in rare watches collector
i assume it was original, however considering the price and the condition (its worth
)
probably u can ask the seller to open the back case, find whatever number of the model inside (mostly 7s26)
the heart of the watch is its movement.
if inside written Seiko, thats fine as well - as long not some china movement
btw those vintage watches comes with maintenance, i bought SNk809 from a friend - theres some rattling sound.
after service - RM 100-120 it works almost a year now
wish you the best. welcome to Seiko