Help needed with Newall DRO

[Micktoon]

Hi All, I am after information on a Newall Digipac 4 DRO , either a manual or used guide or explination of what does what on the keypad. I also need one scale reader as shown in the following photos.
  This is the main unit I think 1980's vintage ?

  Its a 2 axis Newall DRO with one reader missing and a fault on the imperial/metric switch on the keypad, it all seems to work other than this. I was taking it apart to see how the kaypad was constructed to see if it looked possible to repair the metric switch somehow. I was then lucky enough to have a visit from Bob KRV3000 just at the right time, well anyone that knows Bob will know he can not resist ripping things apart and fixing them lol , so as I put the kettle on for a cuppa Bob was taking the thing apart.
  This is what Dr Bob found.

  The circuit board contact second one down on the left hand side had been repaired before with solder, this had shorted the switch contacts so the display was jammed on imperial, this photo is after Bob had de soldered the area and made good. The front plastic cover with the kaypad printing on it has small metalic discs bonded onto the reverse side, these make contact with the circuit board behind as the keypad is depressed from the front.

You can see the solder repair th the circuit board better here. I am glad to report this did the job and it now switches from imperial to metric as it should, the plastic was then stuck back down and the unit reassembled.
 I now need a reader head , I think called Spherosyn ?  as shown in the following photos, its 130mm long, 50mm tall and 40mm wide, a scale bar of 15mm runs through it, I have the bar and brackets just need a reader head like this. The plug is as shown too, the smooth round collar pulls back so the plug can be unplugged then released and the springloaded action locks the plug in place. The plug will be about 15-20mm round.


 
 

 I have looked on the net for info , Newall do not have anything on the Digipac 4 and from past experiences of contacting companies about old goods its a waste of time. I could not find anything on the wider net either.
   The help I need is any info on the unit or a manual and also a scale reader head does anyone have one of these or know where I can get one second hand ?
  Thanks goes to Bob for his magic touch on the circuit board, good timing Bob.
  Cheers Mick.