FWIW I went so far as to check some Aussie auction sites and contact a couple of Aussie parts suppliers...they weren't very much help, except to say that, even down there, the sealed-beam setups aren't easy to get a hold of and are ridiculously expensive (like over $500 per side ) when you do find one.If you want sealed beams on a bricknose truck, get a hold of someone from Australia, most of their trucks of that body style have sealed beams. It is on my own to-do list...
OTOH, maybe they were just trying to get this bloody Yank to quit pestering them...so, maybe someone else (especially with contacts in Oz) would have better luck?