Landeron Cal. 47 Antique Watch Part Vintage Movement Repair

This is an antique watch equipped with Landeron's Cal.47.
It is a rare watch with the brand name Arbor Sport.
It seems to be a military watch that a friend living in the United States purchased about 5 years ago.
The value of this watch lies in the fact that it is equipped with the Cal.47 produced by Landeron.
This mechanism is a hand-wound chronograph manufactured in the 1930s and 1940s, and it is highly reliable and was also used for military purposes.
Operation has been confirmed and there are no particular problems as a hand-wound chronograph.
The exact daily difference has not been measured, and it is difficult to measure the exact time because it is an extremely old watch, but there should be no extremely large deviations (daily difference of 5 minutes or more).
Case size: 1.34 inches wide (excluding the crown), 1.77 inches long, and 0.51 inches thick.