Here are some pics of a rusted out 75 TA.
https://www.dropbox.com/s/5z4hye3trb...e%201.JPG?dl=0
https://www.dropbox.com/s/hg8teornz4...e%202.JPG?dl=0
https://www.dropbox.com/s/7jamhcat5a...e%203.JPG?dl=0
I don't think the wiring loom you have is the correct one. It's different from the ones I have and I've seen for these cars.
Here is a link to E-Bay with one that I think is correct.
http://www.ebay.com/itm/70-81-CAMARO...BXUZED&vxp=mtr