FredC wrote on May 22^nd, 2020 at 2:16pm:

With all the long barrels sawed off to make sporters and faux carbines. There has to be a lot of barrel ends that were not thrown away. One might look for these and remove the original front sights to have a supply. It would not be too hard for a machinist or a gun smith to make the appropriate dove tail to slide them in and finish braze or silver solder.

One would think but I have never came across a barrel stub with the front sight.  I think they must have gone in the trash can back "in the day" with the survivors sent off during WWII scrap drives.