The NatAmi project looks very interesting. We are going in a slightly different direction - they are making a more powerful Amiga, while I wish to clone the original machines as accurately as possible for a low cost.
I can add some new features such as high screen resolutions and interfaces, but I don't plan a 3D engine etc

I'll have a chat to the guys.
My C64 code is based on Peter's design (same codebase as used in C-one) however the SID is not available. I had some code from another party but I can't open source that either, so I decided to write my own. There is some pretty detailed documentation from the die scans now. Frederic, if you wish to share your code I would be more than happy to come to some deal. Mail me directly.
Best,
Mike.