I recently stumbled on this listing and it has what appears to be an authentic vintage 1940's Frank Sinatra Signature with the swirling "F" letter. What do you guys think?
We know that was done, the connect, but not usually. I don't think that example helps your case. In your 1944 example look at those 3 large loops with gentle angles, the spatial relations, the long cross of the "t", the baseline, the lack of the break mentioned. I don't see any of this in the postcard example.
Not trying to make a case. Just put my two cents in and that's all it's worth. Autographs can be like politics, minds are not easily changed once they are set. It's an interesting topic and worthy of discussion.
In case that was not obvious, that is your example and the postcard upside down and backward - spatial relationships and negative spaces inside loops look problematic.