Z-Systems RPD 1: Need a remote

I recently purchased a Z-Systems RDP 1 vintage digital pre/eq.  It did not include a standard  remote--no remote at all in fact.  At this point, after searching the web and messing around with the unit,  it is obvious that use of this unit is greatly enhanced by the availability of the remote.

So, asking any owners or previous owners about this.  I have seen some posts on various forums about trying to get the 'codes' from z-Systems and programming other remotes, some efforts to get the Harmony brand with the codes available, etc.  But no real or recent info about success at this.  Can anyone point me to information on getting an original remote or somehow getting the codes on/into an aftermarket remote so that I can use them with the RPD 1.  Thanks in advance for any and all responses.

Regards,  Rich