Disklavier

I'm trying to find out information about a Japanese Disklavier. Its a 
glossy black Yamaha UX1 piano with a separate control unit which has 
the model number PPC5R. The control unit has an LCD readout (in 
english) but the only buttons are On/Off, record, play, stop and track 
select. It has Midi in and Out only, no audio. It is a Japanese import 
but unfortunately here in New Zealand these are the only disklaviers 
that ever seem to appear on the market (and even then they are 
extremely few and far between). It seems to play beautifully both from 
diskette (DD only) and through the Midi ports and the piano seems in 
very good condition. The dealer tells me it is a 1990 model piano. I 
have tracked down a japanese service manual for sale online and at the 
moment my only option seems to be to buy the manual and somehow have it 
translated. Does anyone here know about this model, whether its a MkI 
or MkII or a place where I might be able to find out more?

Many Thanks.

David Downes.