His signature was very capricious early on and did change quite a bit from the late 30's up until the late 40's/early 50's when it started to take on its consistent/recognizable form. Here's a similar item to yours that was undoubtedly signed in the same hand.
A while ago I thought these could be an outside possibilty of his mid 40's signature but lately not so much. In fact I think I know who actually signed these if I can find where I stored the information. I can elaborate on Wednesday when I have some free time.
Mark O.