I've fitted Newall to both a Myford 7 and a Boxford 280. Expensive, as Raymond says. However, I used an EMS-I display console for one of them as it was a lot cheaper than the Newall one; I already had the encoders. (Note that you need a special display console to read Newall ball scales; not everybody sells them.) The EMS-I version also has a lot more features than my 10-year old Newall console!
Speak to EMS-I and they will help and advise. Machine DRO is another option.
From recent correspondence with Newall, you're looking at about a thousand quid for your Boxford system.
Usual disclaimers.