[darrin]

you should be able to easily find 7" right hand drive (RHD) halogen headlights that would be drop-in replacements for the sugar scoop sealed beam headlights fitted to a us spec Left hand drive car (LHD) -- these move the cutoffs to the other side of the car to avoid blinding oncoming drivers. The sugar scoops were a US DOT regulatory requirement as (if I recall correctly) our regulators were concerned that non-sealed beam headlights (like the $$$ sloped ones fitted to ROW 911s) could get dirty and not illuminate as well. Drop in RHD headlights should be pretty cheap locally as they were used by dozens (hundreds) of different car/truck models.

Unclear what specific changes would be needed for taillights, as I believe the red taillights were a US requirement (yellow side lights should only be on front of car) and that the British authorities wouldn't care about the red taillights you have.