Help me identify the Omega pocket watch.

My greatgrandmother and i are from Russia. My grandmother died many years ago, and i got her watch in bad condition. She got this watch from her brother who died in the world war. After examining the watch, i saw a symbolic "omega" after that i searched a lot for information about this watch. And in principle, i examined for a very long time and noticed several things. A chronometer on this watch. The main cover of the watch is lost, but the second there is a serial number "4506685" "54". The mechanism depicts a hot air balloon. After reading a little history of the watch, i think that this is related to the "Balloon Race" also on the mechanism is the number "44506". Please help me, here is a photo below. i want to know what kind of watch it is.