6 volt system

there is no specific part # for your truck, nearly every vehicle back in the day had round 7" dual beam bulbs, International included,

here is the part # for 7" 6 volt halogen bulb, H6006 it is like the bulb in your truck from outside appearance, same 3 prong connector, but Way brighter,

https://www.napaonline.com/en/p/LMAH6006

Do you have a recommendation for my 6 volt sealed beams, Jon? They dip to the left because we drive on the left side of the road here but they are a little dim. I have upgraded a lot of the electrical system and all the gauges work well but I try to stay off the road after dark with it.

If the headlight adjusters wont adjust because of being made for driving on the right side of the road.
A suggestion I would make is to rotate the headlight bucket 180`.
I think that would help with right/left adjustment but the up and down adjustment may be out of range
Another thing would be to move the adjusters location to suit your needs. The adjuster brackets are probably spot welded to the bucket. They could be moved.
Copy the adjuster locations from a truck on your side of the pond.
Just some thoughts.
check your ground wire for dim lights. a bad ground will do that

^^^what Mike said for adjusting, but for dim, these 6v. halogen are the way to go, And check your grounding too,

And check the grounding !!! Thats why I go to this site !

The headlamps do not need adjusting, they are required to dip to the left. The system is well grounded, the dimness is due to 6 volts in my view. I do not know of any 6 volt halogen sealed beam part numbers that would suit my truck, however.

Wagner H6006 is part # for 6v. 7" diameter dual sealed beam halogen headlamps which go in your truck if it is a 1939-1956 International,

before 1939 some not all had insert bulbs, after 1957 they were pretty much all 12v.

Thank you, Jon