[78-L] Blue wax Columbia date??

[Han Enderman]

Dave Weiner wrote about the blue wax Columbia issues:
The highest East Coast blue pressing I have is 3125-D, recorded in April 1936. 
The highest West Coast blue pressing I have is 3134-D, recorded in May 1936.

However, some time ago, when we also discussed this matter, he already stated that
"The last all-blue Columbia I have is Andy Iona, 3139-D. A West Coast pressing."

The last Columbia issue with the label name (trade mark) in lower case on blue label 
known to me (from image) is Co 3122-D, and the first one known to me with the name 
COLUMBIA in UPPER CASE is Co 3125-D. 
Did they change the label type to indicate the end of the blue wax era?

What is the last known release with the lower case label name?
And: 
How can you distinguish at this time (1936) the West Coast pressings from the East Coast pressings?
Most label images I have with the stamper details visible show A1 stampers.

Han Enderman