The model of the watch is called the Powermatic in the USA. I think you’ll find some answers here:
https://blommanwatchreport.com/2020/01/30/jaeger-lecoultre-e-373-powerwind/amp/
The watch looks very nice. Always good to see the movement to make sure it’s Jaeger-LeCoultre branded to match the dial, rather than a LeCoultre for the USA market. They are mechanically the same (cal. 481 for both), but at that price you just want to know, because a frankenwatch is always worth less than a fully original watch.
Also, be sure that it is 18K. JLC also cased watches in the UK, most were 9K. The hallmarks should be on the inside of the case.
Good luck and I hope the watch turns out as all original.
gatorcpa