I am looking for four of this style knob for a silvertone radio from the 40's.
Can anyone help?

I have those exact same knobs on my Silvertone 7038. I think it is from 1941. Well, I have only 3... one was missing so now there is a generic replacement there. I wish I could give them to you, but then I wouldn't be able to tune my radio. :(

Antique Radio Supply should have those in stock.
http://www.tubesandmore.com