The linkage on the side of the case is a bell-crank system for the 911 Accelerator. It's removed (or cut off) when installed in a Type1 chassis.
Having done this all the hard way (
http://www.germanlook.net/forums/showthread.php?t=11341) I would highly recommend talking to Alex from Bug@5speed, and ordering their conversion parts. It will solve you hours and hours of headaches, where I would often get to the end and think "well @#^&. They're stuff is way better then what I just built." Alex wrote a "how to" thread which can be found here:
http://www.germanlook.net/forums/sho...ht=901+install. For the speedometer output, you either swap your nosecone to one of his (solves multiple problems) or figure out how to cut up the stock output and reseal it as I did.
-Dave