My friend has one and I swear it has a palladium nib! Perhaps he changed it, i don't know. By the way, I'm in the market for an Opera Master as well; how did you find it weight and dimension wise, compared to the London Fog? I have a Florentine Hill and it's the perfect size for me.
He definitely changed the nib because as far as I know all 3 limited editions of the Visconti pens were only released in the Australian market featured the 18 karat nibs. I got the 1st model in the line up the Kakadu LE #100/100, the 2nd model was the Australis which is numbered to 150, and the last one (my memory seems to be faint on that one) just that it was a Opera sized pen compared to the 1st two models which are slightly smaller in demensions than the Opera Master (Kakadu) or the same size as the Opera Master (Australis).
Both are mighty nice pens, the Kakadu is actually a blue pen, it looks black in most pictures you see out there. I'll probably include some picture later on so you guys can see it. =)
Hope that helps, I believe the Kakadu is more comparable to the London Fog than the Australis (Still size wise the Kakadu is still much bigger). Better yet the 3rd model of the Australian LE series is the one you would probably like. Although note, going with the first two versions you will have a HUGE amount of ink capacity. I'll be measuring mine to find exactly how much ink it holds pretty soon!
If you can get your hands on either 3 models, you will be mighty happy with them. =D
BTW, the 18Kt nib that comes with these models are a perfect balance between the normal Palladium nibs and the 14K nibs that Visconti offer IMO.
Edited by ItwasLuck, 28 October 2016 - 16:31.
Dr. Jafar Mohammed Uddin (MBBS.)
Daily Drivers = Visconti Kakadu LE #100/100 - 18Kt Gold 'M' Nib -- Visconti Homo Sapiens London Fog LE #785/888 - 23Kt Pd "1.3mm Stub" Nib -- Pilot Custom 823 - 14Kt Gold 'M' Nib
Currently Inked with MB Toffee Brown, Akkerman #10 IG, and Akkerman #10 IG respectively