There is a pair of ferrite 604 on ebay. One of them has a big chunk of the frame missing. Seller claims it was not dropped, but was screwed down too tight. Have you guys seen this happen before?

Altec 604 8k Pro Speaker Duplex Coaxial Speaker | eBay

I had a pair of 16? 421 frames that were tweaked (bent in two places). I figured that would happen before the frame would actually crack.

Seems like there were defects in that 604 frame. The other one of the pair has what looks like some small cracks also.

Second one

Altec 604 8k Pro Speakers Duplex Coaxial Speakers | eBay