I have seen the internals of a DV-W58E and they are in no way similar to any other drive other than maybe the upcoming 12x Teac which is also supposedly manufactured by Teac. The DV-W58E uses a Sanyo chipsets similar to Optorite/Plextor drives, not Philips (BenQ) nor NEC.
It is interesting that some drives come with firmware 2.0B yet the only available firmware update for the drives is D0JA. I initially thought that there might be two different hardware designs released under the same model name, but The Dangerous Brothers did not agree and said that they are the same. They would know since they've recently spent a bit of time disassembling the firmware and creating a Region Free patch of D0JA
Other recent drives from Teac appear to be unlike any other manufacturer and are likely manufactured by Teac as well.