Just a suggestion but I would be inclined to contact Newing Hall's UK agents to enquire the cost of testing / repair of your existing control box. This assumes you have the Newing Hall engraving softwares etc.
Building a new controller for your machine is quite involved, but it is not rocket science. The Chinese boards are cheap enough but their quality can vary (although I use a Chinese control board without any issue).
The next problem is choosing the motion control software etc. that you plan to use with the machine and this is a matter of personal preference (I chose to use Mach3 which allows me the options of GCode, HPGL and DXF image input with a multitude of CAD / CAM support).
Looks you have to make a difficult decision.
Tweakie.
CNC is only limited by our imagination.