Aah, the never ending dream....
Took over a year to find mine and I did hundreds of miles during the search. Just keep your eye on forums , ebay and the more obscure market sites, particularly 4x4 sites.
Why do you want a petrol one? Bjs are more common (if that's the right word to use when talking about 40s) and the 3B diesel engine is pretty indestructable. Also if you wanted to go for a bigger engine the diesel options are greater - 60, 70, & 80 series engines can all be made to fit.
Worth looking on French ebay, or Holland, or Germany or , of course, Oz and import it. People on this forum have experience of importing. Your best chance of finding a rot-free one is Oz. Mechanically they are very robust but if you're not into bodywork be very careful.
Occasionally I get to hear of 40s for sale, what's your budget?
Happy hunting
Regards,