When Voldemort was tracking the Wand in September of 1997, he looked for Gregorovitch. The wandmaker no longer lived at the same address, and Voldemort murdered the woman and children living there out of spite; this may have been Gregorovitch’s family (DH12). When Voldemort finally tracked Gregorovitch down, he tortured him, entered his mind to see that the Wand had in fact been stolen by a fair-haired, merry thief, then killed the wandmaker (DH14).
At the time of his death, Gregorovitch was a heavy-set man with white beard and hair.
On the now-defunct website HarryPotterWallArt.com, Gregorovitch's first name was given as Mykew. However, this is strictly non-canon.