Sorry for the delay responding. I live in Daytona Beach, FL, and we got whalloped by Hurricane Ian last Thursday. We're fine and no major property damage, but my internet connection went out early Thursday and we only JUST got it back late yesterday, so I have lots of catching up to do.
I bought a cheap DRO kit from eBay for my MX-210V:
https://www.ebay.com/itm/384487676170 I had to shorten one of the scales (for the Z-axis), which is quite easy to do. There are plenty of YouTube videos showing you how. If I were to buy again today, I'd go instead for one of the LCD displays. For example, I recently purchased this display (plus appropriate scales) for my PM-30MV mill that will be arriving soon:
https://www.ebay.com/itm/185535141971 Having both side-by-side, the LCD just looks so much better, and it's not much more money. It also has spiffy visuals for hole circle patterns and etc, but those advantages would be wasted on a lathe.
Of course once your DRO display and scales arrive, there's a considerable amount of work to find suitable mounting points and to construct brackets so that they'll work properly, be as out-of-the-way as possible, and stay debris-free as much as possible. I'll take some pics of my setup when I get a chance and post them here. It's not perfect but a pretty good compromise, I think.
As for the Clough42 ELS setup, that was a real adventure, and I learned a lot in the process. I used my 3D printer to make a suitable bracket for the encoder to squeeze into the small hollow in the frame behind the control panel. And I printed some gears to make use of the existing change-gear arm to connect the spindle drive to the encoder, which again just barely fit but worked out well. (Once my mill arrives, I plan to use it to make steel gears as my first milling project, although the PLA printed plastic gears have been working just fine.) I can upload plans for those 3D prints too if anyone's interested.
There's no place available inside the lathe's change-gear cover to mount the servo motor, and mounting at the rear would cause significant "clearance" issues with the drive, so I mounted it in front -- similar to what James did in his prototyping of the ELS on his lathe. I used a 60T-to-10T reduction, but in hindsight, I'd change that to 4-to-1 reduction. I find that my servo has plenty of excess power available, and it'd be nice to have it run a little slower (though I've had no problem with the 6-to-1 reduction).
I was able to find a place inside the power supply area of the lathe to mount (on some standoffs) the TI microcontroller board, and added a small fan on the side and cut some exit vents in the cover panel for cooling. I mounted the power supply separately on the wall behind the lathe, with a cover to protect it from chips. Again, I'll take some pictures and upload them when I get a chance.