I can see striations in the chip, I'm afraid, so I agree with Christine.
Most of my IoWSG bits don't have flat bottoms, but the well-shaped base and the flame logo.
My Petit Fleur has a heat finished base - it's shiney, but wrinkled, I have another small early piece which is the same (shiney, but wrinkled).
I have two mushroom things which do not look like seconds to me, but have ground, rather than polished, bases - however, I haven't yet had them positively id'd as IoWSG.
Thanks for the reminder that I need to find this out!