What pin do I need to attach the hand brake to the calipers and who sells them?

I would contact AutoAtlanta. They have those hard to get parts. Part number R99916605502

GENUINE PORSCHE LOCK RING
RN0126452 - Replacement/OEM

They also have Rubber SHIFT SLEEVE G91442459100 - Genuine Porsche

I replaced these this year.

http://www.autoatlanta.com/porsche-parts/914.php

Order By Phone: 800 792 4944

I would check with 914 central first if you want new. A long shot maybe but worth a shot. I am sure a number of them are available in the used market. And of course fabing one would not be that hard.

8mm (I think) fastener & self locking nut

FDLFBFAA

Thanks, will check Home Depot.