Saw this at an antique store today. Can't seem to find on any info on google. Somebody guessed that it may be a Six Flags 1.9M visitors limited edition watch.

 

That doesn't look like something Seiko would produce. No logo?

Maybe an exec at Six Flags purchased some Seikos to be customized / redialed to commemmorate an event, achievement, or milestone.

This is all pure speculation on my part, but I would bet that dial didn't come off a Seiko assembly line.

More watch details - like movement info, serial number, etc. - might help someone who actually knows what they're talking about give you some definitive info.