I don't know which Puma you have but the original transmission for my GTC was from a VW type 3, the main visual difference in the swingaxle transmission is the brakes supplied with it. The trans is a long axle version which allows for the type 3 brakes. These brakes are wider that type 1 and the drums are hub mounted and removable without un-torquing the axle nut. I have since converted my swingaxle trans to an IRS trans and disc brakes.
Which shifter rod are you referring too? the rod from the shifter to the coupler or the input to the transmission?
I also have A GTC--- most of my problems have been the person that had it be for me took it all apart and then put A 6volt trans in with all the wrong mounts and many other things------Thank you for all the info it helps--Harvey Montgomery