Do all 16-pin SAD-512 chips have the same "good"/"bad" side?

[Mark Hammer]

I recall the days when diskettes arrived, labelled as "double-sided" or "single-sided" (with half the storage capacity).  One could buy a little punch (I still have one somewhere) that could pop a little notch into the corner of the diskette jacket and magically transform a singe-sided diskette to double-sided, saving one a not-insignificant bit of money.  Being single-sided did not necessarily mean the other side was "bad" - just that it had not been verified as fully usable.  I suppose the companies churning them out saved some money somewhere in the process.

There are 16-pin Reticon SAD-512s that look like the 1024s, but have only one set of 512 stages that is usable.  Are they always on the same side of the chip?  Is this a case of the "other" side not being guaranteed, or is one side systematically disabled during production?  Is this a case of them being electronically identical to the 8-pin 512s but Reticon hadn't set up to use the smaller epoxy form?