I came across a 1909/1915 signpainting book on Ebay, there are a lot of copies for sale for outrageous prices none of us are going to pay, but, this book has really great examples of the ways eyecatching signs were made with flourishes and cool techniques

the cleanest copy is https://www.ebay.com/itm/267308359471

the posting with these nice pages in display is https://www.ebay.com/itm/306551525418

another with other pages displayed is https://www.ebay.com/itm/235961627791

other places to buy are ABEBooks  https://www.abebooks.com/servlet/BookDetailsPL?bi=31682787441

there is another version, that no one online is showing the pages of, it's Atkinson Reproduced in Color and is probably far more satisfying to look at 
"This book brings Atkinson's 96 sample sign designs to life. Atkinson Reproduced in Color presents all 96 plates, fabricated and painted as Atkinson described."

and this, on Thriftbooks is possibly the same book with a different cover

for only 23 to 35 dollars on Ebay, Etsy, and Thriftbooks

but for 1/8th the price of those books everyone is trying to get 180 dollars for, this one is about 25 on Amazon... but again, no look inside of the pages for a good comparison

Frank H. Atkinson lived in Chicago and worked mostly for Cadillac. https://luc.devroye.org/fonts-52976.html