[Ron Ramirez]

Well, that proves that Philco started using larger escutcheons on those sets (60, 66, 38, 39) before the end of the 1935 season.

Now the question is...did they start using larger dial scales at the same time as well?

I found a possible answer in the August 1, 1935 Philco Changes in Models Bulletin:

   

This could indicate the introduction of a larger dial scale and escutcheon as well, which would mean the 66 received it before the 60 and 38 did. Just guesswork here, since I did not find any concrete evidence one way or the other.

You can find a set of Philco Changes in Models bulletins here:
http://www.philcoradio.com/phorum/showth...hp?tid=215

Edit: Upon further reading, the same bulletin states that Model 60 received a dial scale with larger figures starting on 1-1-35. It seems reasonable that this could imply that the new scales were larger, necessitating a larger escutcheon for models 60 and 38 and possibly 39 and 66. Again, just guesswork.