Erla was an old radio company from the twenties that blended into Sentinel in the thirties. I believe your set's schematic is the following indicated as model 46A in the Sentinel listing from "pre-1938." Your sticker on the radio back says made in plant "S" which tastes like Sentinel.
It's an 8-tube set with tuning eye, and from what I can see on your pictures, the tube lineup looks right compared to the tube layout on the schematic. Have a look and compare to your radio.
http://www.nostalgiaair.org/PagesByM...7/M0018207.pdf