[78-L] Johnny Marvin Signed Test Pressing Label?

[Clifford Bolling]

Greetings.  Hopin' someone can help with this - 
 
I would like to confirm whether this could actually be a Johnny Marvin signed record label:
 
http://pdx78s.cdbpdx.com/JMTP/JMTP.html
 
I've looked at a bunch of Johnny Marvin's sheet music with his signature and it seems to consistantly match pretty well.
 
This is a Victor test pressing from 1930.  Would it be really unlikely that an artist would make a note on a test pressing 
label like this?  
 
Listen to a sample here:
 
http://pdx78s.cdbpdx.com/JMTP/Sample01_LAZY-LOU-SIANA-MOON_Johnny-Marvin_VICTOR-Test-Pressing_Take-2-cr_.mp3
 
This is the unissued Take 2 recording with the Nat Shilkret orchestra.  The issued release was Take 4 with the Leonard Joy orchestra, recorded a few days later.
 
Thanks!
 
Cliff