Rare 1966 Seiko 5 Sportsmatic 6619-8120 silver pie pan dial w/ box extra strap

OG very rare 37mm 1966 seiko 5 Sportsmatic pie pan dial 6619-8120 automatic movement I've never popped the back off, but I do know it's been serviced it runs around +/- 7spd, so it runs really good for a 66. I've had it 12 yrs. my dad bought it new way back in early 67. I know he had it serviced, but we can't find any of the paperwork. I've run it on the winder at least once a month and / or worn it out to dinner or something so it's never js sat for long periods of time. day/date functions as it should. Case has never been polished or touched other than the servicing years ago. has some scuffs on Crystal and case, of course, it's a 1966 lol it's a 37mm case w/19mm lugs. fairly new Kreisler leather strap and brand new never worn 18mm strap. Just use spring bars already in watch if u use the Barton.. nobody will notice its a half a millimeter shorter on each side lol