The engine won't care if the line is crimped but the line might not be happy to be reattached after being crimped by vice grips.

The triple gauge out of any 78-85 300D will probably work. The experts can tell you which years will definitely work. See what's being offered in the parts forum. I wouldn't worry about part numbers for now. If it was a kludge before you got it, it might not be the original triple gauge anyway.

Sixto
87 300D