here is what I found out a while back
swapped in an NP435 years ago and having a 66 I have had no need for back up lights.
Last trip to the junk yard I yanked some real clean light buckets and lens (off a van - sadly van chrome did not fit)
Moving slowly but forward I needed a plug in for the backup light switch on the NP435
here is some part number that may help if you are wanting lights for your NP435
NP 435 backup light switch harness repair end
ECHEC193 Napa
PT5673 Pico
If you want the full harness
WPT826 Motorcrat
The switch is an
SW80 napa