If I understand the federal laws correctly - an individual person can sell a homemade firearm (In this case, a complete AR15 built around an 80% lower milled out at home)  if the firearm was not built with the intention to sell it.
Does anything in Illinois law conflict with federal law? ( if I am understanding federal law correctly)
If you could direct me to the actual text of the Illinois law that would be great.
If there is another thread on this topic that has already covered the answer, please provide a link if you have one.
Thanks.

If there is no statute prohibiting it, it's not illegal. There would be nothing to reference.

I am not a lawyer but I understand you are good to go.

Thanks for the input. My research told me the same thing- but this was challenged by a LEO and by-standing citizen over the weekend, both who probably assumed the lower was completed with the intent to sell it.

When you choose to operate in the gray area, expect to be challenged.   Now that you have made the transfer public, expect it to be scrutinized by LEO monitoring this website.

Let us all know how much you spent on legal fees after you are indicted and the criminal case is adjudicated.

Who made a transfer public?
No past or pending transfer was implied, it was only a question- and I think it was a legitimate one.
And I'm not being sarcastic- but from what I understand completing 80% lowers for your own use in Illinois is not a legal grey area.
It is legal and there are no statues that prevent it.