Being a Zenith guy (I just added a TO 3000-1 to my collection yesterday; won it in an eBay auction), I'm not too familiar with RCA sets, especially the Radiola series. How does yours sound with that external speaker, which I would think is as old as the radio itself (I'm guessing 70 years or more)?
BTW, your Radiola set looks great for its age. How much restoration work did you have to do on it, besides the usual recap, replacement of dead or weak tubes and burned-out dial lights, etc.? The cabinet looks great too.