Hi Splat
I looked at the hole on the chuck side of the cross-slide but there is no gib over there on my machine, so the point of any screw would drag directly on the internal dove tail, Plus my follow rest mounts on that side, so I think that is a no go.
The solution in DarkZero's link is interesting, particularly for the older magnetic scales, but after further contemplation, I think I may move my gib screw towards the front of the lathe about an inch or so. Then there should be plenty of room to mount the new shorter super-slim magnetic scales on the aft side of the gib screw (see pic below), and the read-head on the aft "outrigger" of the saddle. Will likely have to remove the cross-slide to drill and tap the new hole for the gib screw but that's no biggie. My cross slide travel is only about 6-1/4 inches.
Bob Korves makes a good point about the tailstock crushing the scale and/or read head though. Maybe a simple bumper will prevent that, but the tailstock will then have a shorter reach as Bob points out. Either way, I think I'll change the gib lock lever to a screw and use a dedicated little box end wrench. The lever is kinda clumsy.
The whole shooting match could be mounted on the chuck side of the cross-slide, but then it will be under a shower of schmutz all the time, and you run the risk of crashing the scale/read head into the chuck.
Will try to find reference to Jim Dawson's solution.
I'll call DroPros next week for more info. I really like EL400 digital head I've had on my mill for about 6 years. Won't be too happy to change heads but alas.