http://k53.pbase.com/v3/09/553709/2/...4.L1000356.jpg
Here's a picture of what at first glance appears to me to be original linkage. it was a quick google image search for 1966 pontiac tri power. It's not too up close but int he future when you see setups, at least you'll have a better idea of what original more or less looked like.
I know AMES and Performance Years sells repro linkages, ebay usually sold a good little kit for about $100 with most of the pieces. Just mentioning some options!