The 1306 is a mystery amp. I'm not even sure that this is the actual number of the amplifier. I've only seen limited pictures of one example of the amp, and there were no definitive markings or labels present to make a positive ID. The dealer that had it up for auction said a typed manual was with it and indicated 1306 as its designation. There was no Silvertone logo or other makers mark on the amp chassis, and the sole catalog listing I can find assigns it no catalog number.
 

Only available listing:
Fall/Winter 1946