I just won an uncoated 10" aluminum record at eBay. I bought it only to 
have an example in my collection. The record seems to be pre-grooved, 
but on the use side only. I've heard of pre-grooving but not as late as 
the label suggests, which would nave been sometime around 1942. I'm 
surprised that the embossing machine was even in use that late at an in 
house studio.
The label is a whole 'nother story. The disc was recorded at/for Radio 
Recording Studio (RRS) which was located at 1619 Broadway in New York 
City. The phone number is Columbus 5-9037 and, yup, that would be in the 
Brill Building. For the 5 bucks I paid for it I'm happy just to have the 
label!
The handwritten  title on the red and cream label is "Celeste - Aida" 
and the artist is as "Sung by Chauncey."
Any further info on this label and/or recording studio would be 
gratefully accepted.
Malcolm R