I know this is a group build and perhaps emphasis is not 100 % (?) on details but I thought I´d share info. on this device perhaps of interest to you and others building a late Jagdtiger version.
As it´s broken on the Kubinka Jagdtiger, Dragon obviously guessed what it actually looked like but I have found an original drawing. The drawing is to big for my scanner so you have to do with my doodle:
In the post by Mirko in the photo of the Kubinka vehicle you can hint the right side´s handle.
I´m sure more than just the Kubinka vehicle had this device and I´ve found photo evidence of it on s. Pz Jg Abt 512 vehicles as well, perhaps more of this later.