Since finding an antique brass barrel type lock with rotating disk letters, I've kept an eye for others--this is not that, iron/steel rather than brass, and with numbers rather than letters, but still. I do not have the combination, so it is also a puzzle to be solved! (I also think that locks make nice valentines!) The numbered disks at the far ends are fixed; it is the three center disks that turn. Made by G&J Gem Lock Company, NY, late 19th c. or so, I believe.

1 7/8" t x 1" d. and in well used antique condition. The three center disks turn, sometimes requiring some pressure (I believe they tend to get tight when in or near the correct combination!)