custom lettering

Lettering classic artists from the 50's, 60's and 70's

Good morning everyone,
First of all I want to congratulate you for this group, I have learnt a lot from all of you and your daily posts about sing painting.
I am running a research on "signs" from the 50's, 60's, and 70's, I have found a lot of classic designs of lettering in advertising but I am looking for the artists' names who created those beautiful letters. I would like to know if you can provide some information for me.
I really appreciate your help.
Kindly regards,
Felipe Calderón