I was wondering if the RHD would be difficult in the LHD world, what makes it difficult?
I noticed that this shop seems to have a lot of 4 light rigs-must have been a popular thing at some point. Does having 4 headlights tax the electricals at all? I guess I should find out if they all do work first.
For me it is. Some people have no problem (like your postman). For me it's about the visibility and shifting coordination, not to mention the visual perspective for the driver is changed (think merging onto a highway). I've driven some RHD vehicles, and they took some getting used to. Can't say I liked the experience, especially when I was switching between LHD and RHD. YMMV. Just something to think about when you're looking.
As for the 4 headlights, if functional they would be a custom wiring job. The quality of that work would determine the effectiveness of the lights. I briefly considered installing a Series IIA grill on my Rover to get that look. Seemed like a good place to mount some round auxilliary lights. Of course, the wiring would have been through it's own relay to the battery. I certainly wouldn't have spliced the extra lights into the existing harness, because of the risk of taxing the wiring with amperage it wasn't designed for. Dim lights and heat are usually the result. There may have been a bit of fudge-factor included in the design, but I generally don't trust much wiring that's older than I am in a vibrating environment. Besides, any time you cut into the wiring harness you run the risk of letting the smoke out. NOS Lucas-brand smoke is becoming increasingly hard to get, and the Britpart replacements aren't nearly as effective.
Pop the hood and look how it was tied in (if at all). There's not much of a harness there, so it should be easy to trace.