I just checked the Official Rare Collectibles topic to see if it held an answer for you; but little luck, I'm afraid. The numberless Disk is listed (as quoted below) in the ultra-rare category - and there's a picture comparing it to the standard Disk of Time, if that helps any - but the "$??" means, in the thread's own words, that the item "cannot reasonably have any value associated with them because they haven't been sold even once".
Numberless Disk of Time - $?? (comparison with regular Disk of Time)
A very rare version of the Disk of Time that lacked the number 199, presumably a misprint. Owned by Toa Lhikan Hordika. Another was found by BZP member Dr. Johnathan Crane in a Keerahk set that was meant to include a regular DoT, but was destroyed.
Still, I hope that helps a little, at least?
Edited by Darth Jaller, Sep 03 2017 - 04:43 PM.