That all sounds reasonable. It's analogous to what science says about energy and matter: energy changes its material forms.

But are those forms illusory or does it make sense to attribute limited reality to them? If the latter, and you accept that the body is real for a time, even if the real body never conforms to our conceptual idealizations, I think the Buddhist is led to agree that the self is real in a limited sense.

The self is mainly the activity of the brain that's ensconced in the body's head. It's one thing to say we're not what we think we are (because we reify our concepts), but it's another to say we're nothing at all or that selves don't exist. You don't have to be eternal to be real.