[Arran]

I don't know if anyone in Philco actually designed these rosette style knobs if or someone at the knob manufacturer did, I have seen very similar knobs used on Majestic radios (and Deforest Crosley at least in Canada). I have never seen any references to the stylist behind this knob design and how they were developed, it could have been an "off the shelf knob" that Philco simply chose to use. Many manufacturers did this to save costs, especially with Bakelite knobs, as it was much easier to design a cabinet to suit a set of knobs then the other way around.
Best Regards
Arrn