I have worked on many push button trannys ('62 to '65)and have yet to see one with a parking brake drum on it.It must be a '50's model. One thing is for sure,you don't want this one.
i had a 62 dodge that had a 361, pushbutton 727 and a parking brake drum on the tailshaft housing. all original.
true, you probably do not want the headache of this for your application, but those maxwedge guys love these transmissions as they are hard to get parts for.