AFAIK there are other instances of pedals being produced way past their "official" production end. I think the CE-2 is claimed to have been officially discontinued in the mid 80s and yet there have been people here who have serials dating their pedal to 1990.
He does make a good point about the serial range conflicting with the od-1 date's range. If you punch in the serial 890000 like the OD-1d, it gives you April '88. Maybe Boss ran limited runs for the last few years after reportably ending production.
Nice condition, wish i had the coin for it at the moment
The seller is correct, the latest OD-1 observed so far has a serial number 92xxxx so the pedal was produced until late 1988. The dates given by Boss are from their marketing department and doesn't always reflect the production span. Some pedals like the CE-2 and OD-1 was produced for many years after the reported sales date end while some pedals like the PN-2 or PW-2 was only produced for a whort while but the sales department kept marketing them for much longer.