70 dual snorkel air cleaner question

[fireguyfire]

I'm restoring a rough dual snorkel air cleaner to go on my 1970 383.
I ran the lid through the bead blaster today, and I noticed that on the underside of the air cleaner lid it appeared that the center part underneath where the pie plate goes was black, but the rest of the bottom of the lid (outer part) was unpainted.
Is this observation correct?
I know it seems crazy to be worried about how to finish the underside of an air cleaner lid, but it doesn't cost any more money or time to do it correct, so why not.
Obviously the outside of the air cleaner will be wrinkle finish.

[anlauto]

Yea...I don't think the original manufacture were too worried about the inside of them...