Picture 1 - These first two pictures show the engraving on the older, 1933 horn.
The engraving is entirely above the band where the bell is connected to the bow.
And the engraving is either more sedate or more stately, depending on your frame of mind.

Picture 2 - another picture of the 1933 horn.
The engraving is faint, but I don't think it has been buffed. I think it is just worn.

Picture 3. Here is the engraving of the 1937 horn.
It is larger, extending down onto the bow.
Seems livelier or 'louder'.

Picture 4. Keyguard of the 1933 horn.
One thing I'll point our here, the 1933 horn had nickel key arms and touches while the keypans were lacquered brass.
The keys of the 1937 horn were totally nickel-plated.

Picture 5 - 1937 horn keyguard..

Picture 6. See how the 1933 horn the High E key has a bump or ridge on the keytouch..

Picture 7 - It is gone from the 1937 horn.

Picture 8. The 1933 keytouchs are sculpted differently. The octave mechanism more simple.

Picture 9. 1937 horn has changes. The thumbrest is much nicer.

Picture 10- the octave mechanism of the 1937 horn is more complex.

Picture 11 - On the 1937 horn on the left, the High D has an arm that holds the High D# closed.
Or is it that the High D# uses the arm to open the High D.
Restated: when Hi D# is open, Hi D is also opened.
when Hi D is closed, Hi D# is also closed.

Picture 12.The Low Bb and the low C# keytouches are much larger on the 1937 horn.