[Jhunt]

What do these numbers mean, the knobs are from a Philco 19? Production date perhaps

[Ron Ramirez]

Only dead Philco engineers know the answer. And dead men tell no tales.

[RodB]

Hi JHunt,

Now all the collectors will be scrounging through their parts boxes looking for a matched set. lol

[Jhunt]

Here is a pair of Rosette knobs that match, but the backs are different.

[Brad Winder]

Oh great...more "numbers matching" LOL!

I think they are probably mold or casting numbers. Or possible it's the number of the machine used to make the casting. Manufacturers usually keep track of details like that, so they are able to track down causes of defects for quality control.

[Arran]

There were some Airline (Belmont) sets that also used rosette style knobs, maybe the one with the different back is one of those? Also I don't think that Philco manufactured their own knobs, at least the Bakelite ones, I noticed a letter "S" on some of the knobs, could that have stood for "Santay"? Santay seems to have made a lot of knobs for post war RCA sets. Kurz Kash was another outfit that made a lot of knobs, their logo was a double "K", back to back.
Regards
Arran