Aloha,
Here is my totally unprofessional report on the IWC IW3583 Portugieser 40 mm replica by the GR factory.
I have bought both the green (IW358310) and the white/blue (IW358304) models for USD 318 each.
Since I don´t have the originals, I can´t compare them to those.
The serial number is 2345678 for both watches. The size is good for my 17 cm wrist. They are smaller than the IW5007 Portugieser but the difference is not that huge.
Workmanship looks good to me but I am not an expert. The brushing on the sides is not very visible. The green dial has a nice sunburst. The white dial looks perhaps a little flat. The blue on the hands and markers is quite intensive.
The straps are a bit stiff and thin. Not sure about how accurate their colours are. I will replace them.
My TD was told by the factory that these are Miyota 9015 movements. Accuracy was measured by the TD to be 7s/d and -9s/d. 28,800 beats per hour. They have a date function and a hacking function. They run for about 44 and 52 hours with 40 turns of the crown. Pulling out the crown is a bit tricky. The rotor can be heard. I haven´t noticed any stuttering of the small seconds hand.
Hope this helps. I am open to your questions.
BP