Thoughts on a IWC 666A Ingenieur

Dear all,
since OF shows a deep knowledge on vintage IWC, I'd like to get some thoughts about this 666A Ingenieur for sale online.
My feeling is that everything is okay, the patina on the dial doesn't bother me. However, I know from experience that with IWC, dial reprints and various inconsistencies are always around the corner. So, I would be reassured by the opinions of some experts on the forum.
I just still miss a pic of the case serial between lugs.
Thanks a lot in advance,
Alessandro

I am confident that the dial is original. The case makes me a bit uneasy, though, and I would want to see more images from the side, and back, along with the number on the inside of the bottom lugs.

Thank you Tony, I will ask for more detailed pics.

It appears to be correct, but I'm guessing that the back my be overpolished, or otherwise not in very good condition. Also, the sides of the mid-case would have contrasting brushing, if original finish.