Vintage Gallet Chronograph Pocket Watch - Excelsior Park Mov

Hi everyone,
I wanted to share a recent vintage find and seek some advice from the Gallet and Excelsior Park specialists on the forum.
This is an open-face Gallet chronograph pocket watch that appears to be an entirely unmolested, factory-original specimen. After carefully opening the case and studying the technical features, I’ve noted the following details:

• The Movement: The watch is powered by a high-grade Excelsior Park column-wheel chronograph movement (a Calibre 15/19 variant). The finishing on the components remains incredibly crisp and bright. It features the signature inverted "Y" chronograph bridge architecture. Crucially, the patented built-in spare parts compartment (Swiss Patent CH100230) beneath the balance wheel assembly remains entirely intact and untampered with. The balance bridge is stamped with the JXR US customs import code, confirming legal distribution by Jules Racine & Co.
• Mechanical Condition: Mechanically, the watch is an excellent runner and appears to keep excellent time. The chronograph functionality engages flawlessly: the central seconds hand starts smoothly, tracks accurately, and snaps back perfectly and crisply straight to zero upon resetting.
• The Case Architecture & Serial: The mid-case is stamped with the serial number 729,748, which aligns perfectly with mid-1940s production windows. The most remarkable aspect of the case is its condition: the snap-back case is completely smooth and unpolished both inside and out. There are zero military ordnance marks, no civilian engravings, and absolutely no hand-scratched watchmaker service inscriptions anywhere on the inner walls. It looks completely crisp, indicating it has avoided the typical over-polishing or rough handling seen on these tools.
• The Dial & Hands: The dial is an honest, standard 60-second layout divided cleanly into 1/5th second increments. It features a dual-register configuration with an elapsed 30-minute recorder at 12 o'clock (featuring the classic extended 3, 6, and 9-minute markers) and a running sub-seconds register at 6 o'clock. The typography, original leaf-shaped handset, and dial plating show beautiful, honest aging without any signs of modern intervention or cleaning.

Given the absolute lack of historical watchmaker markings and the immaculate state of the civilian-spec case, this piece behaves like a true "time capsule" that has sat forgotten in dry storage for the better part of 80 years—yet it operates beautifully.
I would highly value any expert insights into this specific reference. How common is it to find civilian-delivery variants of these Excelsior Park calibres in this unpolished, fully operational state compared to the standard military-issued contracts?
I have attached detailed macro photographs of the movement, the pristine gear train, the dial layout, and the case condition below. Any context regarding its scarcity or general collector interest would be greatly appreciated!
Thanks in advance for looking.
Cheers
Teng