As the fellows above have stated, you can reuse the original rubber-bumper fenders, but the parking lights will have to be rigged since the newer fenders don't have the correct openings and they are in a differnt spot (and there is no normal parking lights that will fit these openings since they were not intended to hold parking lights).
On my car, I intended to put the parking lights in the grill and use the openings as brake-cooling ducts, but by chance, I was given a perfect pair of '62 box-Sprite fenders, so that's what I used. Last year at Watkins Glen, I crashed heavily and wrecked the left front fender, so now my car is sporting one new and one old fender! It looks goofy, but it's mostly a racer, so I really don't mind....I'm actually working out something to make it look better this week.
One thing to watch: there are *two* styles of "older" fenders. One has the parking lights mounted higher than the other (everything else is the same...headlights, mounting bolts, etc.). The actual parking light will fit either one. They look pretty close off the car, but will look funny if you mix-and-match.