Font recognizing tools were useless for this one. Thanks in advance for any leads.

Trafton Script / Quick  Suggested by FontsArena 

Seems very similar to Trafton Script (also known as Quick), which was very popular in mid-century years.

Most notable differences are in weight, lowercase l, and capital S — which can be seen in this type specimen https://www.flickr.com/photos/28813954@N02/11631712765/

Just like Quick, it most probably has not been digitized yet.