Hallo Phil, thank you very much for this compliments! I have also already read somewhere about the preserved colour pattern, which show brown or brown-reddish colours and those denticulated patterns. I have a book with wonderful illustrations by Burian (one of the best paleo-illustrators of all times) which shows some of the nautiloids with such patterns and colours.
If I would make the model again, I wouldn´t make such bulbous eyes (I have no idea why I did this) and would make it more like the last big model. But for the big model I needed 7 hours or so, and for this small painted model I needed only a half hour to sculpt it. I would also sculpt it without nautilus-eyes, and probably without a hood. The big model would surely look ways better than this one if I would paint it, but I would never use water colours, but only airbrush, what I don´t have.
Here are again the pictures from my blog, I made also two uploads in the gallery. The two upper pictures show how I photographed it in front of a book about prehistoric marine life, the one left below shows it painted but still without finish, and the one right below shows it with finish on the base.