No, your White foot will not work. the distance between the presser foot bar and needle bar is 1/2" for the National and 5/8" for the White. The gap the foot clips to is the same, though I've run into many National feet that were just a hair too narrow to slip on the White.
Put the foot on, put the needle down and the needle should be centered in the back of the slot of the foot. It will probably hit the back of the foot. This is very evident with feet that have needle holes instead of slots.
I'd post a photo showing both for you, but photobucket has been down all morning.
Last edited by Macybaby; 01-29-2016 at 09:25 AM.