It didn't need a DRO or scales to be CNC controlled. Many (most?) CNC systems don't actually measure where they are, they just command the motors to go where they are needed and expect it to happen. But you may find that there are screw holes for the limit switches to stop the X and Y axes from crashing at each end unless it was a real DIY conversion. The ballscrew looks like the real deal though and it looks as if you have square ways, not dovetails, so probably a fairly solid machine.
Yes, the tooling will cost you more than $450 but it's worth it. To me, the best investment on mine was a 3-axis DRO, followed by an Align X-axis power feed. These make it possible to do quicker, accurate tidy work that you simply couldn't do manually. Then perhaps you could look at (re)conversion to CNC!!!
Good luck!