Help with identification

I am a new member and this is my first post, so please bear with me. I need help determining what series/variant of Buescher 400 alto I have. According to the excellent I.D. chart on Saxpics, it seems to be one of those ill-defined transitionals which displays elements of more than one series. My Dad bought it for me around 1961-1963, but as I am now 61, I can't remember exactly what year. I am considering selling it, but I first need to determine exactly what it is and how to properly describe it. The description is as follows ( using the Saxpics chart format ) :

Model number : has none
Serial number : 388311
Bell key orientation : left side of bell
Octave key orientation : normal
Gold plated Norton screw-in springs : yes
Snap-on pads : yes
Roller color : yellow
Tone ring : none
Finish : lacquer w/ nickel-plated keys
Engraving : Buescher 400 (vertically)
G# key stamped : Buescher

The support between the bell and the body is a single horizontal lacquered brass rod. The cork on the neck is new. I have the original Buescher hard rubber mouthpiece, and a Selmer C* metal mouthpiece. It came in the gray leather tri-pack case with red velvet, for sax, clarinet, and flute. The case has a metel Buescher nameplate and handles on the top and the end. It is an absolutely gorgeous horn with appx. 99% of the original lacquer, very few light scratches, and no dents. I took very good care of it.
It deserves to be played, not just admired.

Any I.D. help would be much appreciated. Thanks very much in advance.