1st Welcome to Milsurps !
I used to know a gal from Prince Albert...
I'm not aware of any LWB stocks being sent to QHMC, but doesn't mean it didn't happen. No way to be sure without having a CC stamp on it to see who accepted it.
Very possible the original stock was damaged or as you said just got swapped around.
Others will chime in.
In the mean time here are some links I found using our Search feature with some QHMC's near your range....
https://www.milsurps.com/showthread.php?t=67757
https://www.milsurps.com/showthread.php?t=67330
And here in case you haven't seen it a link to LPW use:
U.S. Carbines in Germany and Austria