Hi Clarence-

I do not know, but the original “1936 box” that does not include reference to WRACo as a Division of Western Cartridge Company, was fairly short lived.  According to the Giles and Shuey book, the box soon acquired the Division of Western logo at the bottom…  So I suspect that the two plants, East Alton and New Haven, were already united.

FWIW… If you can interpret the inside flap codes of WRACo ammunition better than I can, here is a photo of the inside flap of my Wimbledon box.  I think the “A” part of the code means the ammo was loaded in East Alton (Western), even though the outside of the box only says New Haven.

I have also read (somewhere) that this match ammo was hand loaded, not assembled by machine.  It would not surprise me at all if your observation about the pattern of bullet holes in the target was 100% correct.

Others should know more that I do about this…

Lou