yes ....the fenders should work, 72 Plymouth duster/scamp fenders didn't change much from 74 Plymouth duster/scamp fenders.
I did the same swap your doing but reverse .....i had a 72 duster and i got rid of the 72 front end and put a 75 duster front end on it by changing those items only .....the fenders stayed put where they were
duster and scamp had the same front end
