Well, I later found that the supports for the fuel lines and brake lines were torn up by the object and my lines were hanging about an inch lower than they should be (having lost the support of the support). I could see sort of a threaded stud that point downward and I think there was a plastic support there.
I have found that a nut meant for a 10mm bolt will thread onto this stud.

I think I'll need to fashion a bracket because the Volvo dealer said the part is not available.

I was pretty lucky to have no damage to the lines themselves.

Now I will be totally paranoid about trucks in front of me. I strive to avoid them but it was so congested....