[Arran]

You can also look here.  I didnt look carefully at what Philcos he makes replacements for but I can say Ive bought replacment Truetone/Detrola stuff from him and they were perfect

http://www.radiolaguy.com/RadioDials-page2.htm

Thanks for the link Jim.  Don't see one there that looks like the 620.  And if it's 65 bucks, that's as much as I paid for the whole radio.

 It also says that it's laminated plastic, which to my reckoning sounds a colour photocopy run through a laminating machine, something that the now defunct Rock Sea enterprises was notorious for.
Regards
Arran