Well, for what it is worth, I think the lower front sheet metal area is just fine. And I am seriously fastidious about preservation and such. I cut holes way back in the late seventies and have not regretted it. In fact, I recently had an opportunity while doing the off-the-frame thing, with the doors completed blasted down to metal, to put metal back in there and go back to smooth metal - and passed that opportunity up. I like speakers down there.