If you still have the original lenses and want to mount the sealed beams behind them, just get one side headlamp assembly from a 60s car with 4 headlamps. You'll use one side in each headlamp.
Center the sealed beam unit in the bucket and weld mounting brackets to the bucket. Mount so the sealed beam is about even with the face of the bucket and be sure you can still fit the original lens and door assembly over it. If everything is OK, weld her up , plug in your headlamp socket and adjust the lamp as usual.
(Note: Always use haolgen bulbs. Since you are using the original lenses and doors to keep appearance authentic there will be a "double-refraction" of the light, but the candlepower will still be far superior to the lens/reflector system of original car.)