Can you lays hands on it in person, or would it be a long distance transaction?
Here's some study material. It got a bit long, but it will give you some more background, perhaps help you ask better questions, or know more of what to look for if you can see it in person.
http://www.thehighroad.org/showthread.p ... 755&t=1430
I agree, it has been modified. It looks like the hammer and trigger have been polished, which may or may not be an issue, depending on how deep the polish went. The hammer, is it's the wide target hammer, has been shortened (ground down) from the rear. The trigger stop is a bit unorthodox, and odd, since these guns had a built in trigger stop from the factory. The blue wear is an unusual pattern, I think it may have had some rust at some time, but it's hard to say without seeing it in person.
All handguns are more rare down under, what may be a pick and choose issue for us, may not be an issue for you guys. It would be about a $250 gun around here with the wear and changes. Supply and demand. If it's mechanically sound, it may well be worth the asking price down your way.
"Far better it is to dare mighty things, to win glorious triumphs even though checkered by failure, than to rank with those poor spirits who neither enjoy nor suffer much because they live in the gray twilight that knows neither victory nor defeat." -Theodore Roosevelt-
Isnt it amazing how many people post without reading the thread?