Attached is an image of a Mazda 15W White lamp I got recently, made in the first quarter of 1944 in Jackson, MI.

I am intrigued because the flicker bands are yellow, suggesting that this may be a halo phosphor lamp, it is also quite bright...

Is it true that fluorescent lamps with halo phosphors were made in the United States as early as 1944?

I know halo phosphors were developed by Osram-GEC in 1942, however beryllium phosphors were not banned until 1949.