Help with front fender seals; are they necessary?

[jsera]

Hey guys, I'm putting my 72 back together now that panels are back from paint and im home from college on spring break. I've just realized i don't have the fender seals or the metal piece that holds them and which clips to the fenders nor do i have the right angle seals or brackets. As I replaced my rotted fenders with new ones.

Are these pieces necessary to put the front end back together and if so is there any substitution that can be made for these? I do not want to hold up work on the truck because these parts wouldn't be in by the end of the week...