can anyone help me find info on the lock, the bottom has PAT by FOSTER, AND HAS ONE DIAL AT THE BOTTOM WITH 7 LETTERS, AND 3 NOTCHES BETWEEN EACH LETTER, WE TOOK IT TO A LOCKSMITH, AND ALTHOUGH HE IS A COLLECTOR, HE SAID HE HAD NEVER SEEN ONE LIKE IT! I HAVE HAD IT FOR OVER 40 YEARS AND IT BELONGED TO MY FATHER, THANKS!