Well, I did find a nub on my firewall where the plastic hoop-style clip would have been. I need to check for the clamp by the steering column. I also need to take a closer look at the trans tunnel and see if I can find evidence of the other clips, and figure out what they used to connect mine to the bellhousing (I swear, it looks like a clamp for the starter cable).
Thanks for the pics and info so far. I know the examples have all been for '69 cars, but I still really appreciate it!