That's looking really nice.

The black strap on the firewall should be on the passengers side inner fender. My Challenger accually used 2 of those straps but only one came in my strap kit.(I cleaned up one of the origonals) Our cars were built very close to each other(October) so I'm pretty sure yours would be the same way. There are two "D" shaped, black plastic clips that go on the firewall.