The caption on the picture said Loening c-2-c, but I'll give evansb full credit.
I was thinking of Western Air Express serving Catalina and Thompson Airlines which ran service between Detroit and Cleveland. Thompson was related to Thompson Products which made engine bits.
There is a Keystone Loening ad showing the Western Air Express plane.
I'll post a couple of pictures when I get to my own computer.
evansb, the field is yours.
seacue
(pictures added)