U.S. denotes a padlock made to order and built to specifications of various US government/military agencies. According to an older American Lock catalog in my possession, Our locks have been in Military Service from World War I.... K1V106962 is likely the key code, presuming a 6-pin mechanism.

...the young inventor's (John Junkunc) other padlock designs were the company's now famous ball-locking key padlock..*

Junkunc Bros. acquired, and became "successors" to American Lock Co. in 1919 see link:
http://www.americanlock.com/the_amer...rican_lock.jsp

*adapted from Locks and Lockmakers of America, rev. 3rd edition, by Thomas F. Hennessy

Pete Schifferli