Here is my take on the Technics/Casio mystery..
I think no way is Technics involved with the design of the MZ2000...There are no common features of the two companies..
First Casio has incorporated the synths of their mid 80's...the CZ series, with most of the synth design from the CZ1[86],,the best of the series...it also includes features of the VZ series...Technics does not use any of these features in their own line...how can they design for another brand?

The other designs are from the CT [top models of Casio]..

The MZ2000 sound technology is continued in the current WK series..


All of the above confirm to me that Technics[Panasonic] had nothing to do with the development of the MZ2000.

If the question arises that Casio had influenced/designed/built Technics keyboards...I would find it more believable[Casio has never manufactured for Technics]..


The only common association...Third party software company, Technote, developed software for Casio, Technics, and Roland[probably others too]..

Parts are still available for the MZ[from Japan], and a lot of the electronics are generic..

That's my view....

BTW...that crack/opening in that area of the MZ, is no big deal...Do the pitch and mod wheels work?
If so, don't worry about that damaged corner...

Which ever board[MZ or PSR] you buy, you will be okay...