The gun in question has plain 'ol "Plain Twist"

ML Twist variants



Twist and Damascus Twist variants by Joseph Juleinond de Nessonvaux



"Best London Damascus Twist" is found on Baker A & B grades and Leaders, Lefever H grades, and L.C. Smith Maker Baker guns



and a very few P grade Parkers



Any pattern labeled as "London" is almost surely of Belgian origin. "London Damascus" was a 2 Iron crolle damascus offered on Ferdinand Drissen's 1897-1898 price sheet.