Why wasn't it functional? Reason I asked is because I had started to manufacture an MDF book build machine before I found the forums & had already progressed a long way before I started to read some of the downsides to them. Because of the stage I was at the advice from the forum was to finish it so I could firstly gain a bit of experience using the machine & the software & secondly because it might be possible to use it to help with the next build. I was advised to buy electronics that I could migrate to the next one so I wouldn't have to buy them again.
You already have better components than I have if you have supported rails & ballscrews. Can't be that far off complete if you already have all the components so may just be worth finishing.