only the early summaron m mount has screws that once removed, could be used on the ltm.
the reason why it cant be done is that there is a distance thingy which was designed such that the
m-mount would be 1mm more than the ltm mount.
If there is is a M to ltm adapter, then you probably need a digital screw mount camera with live view for focus. For M lenses to be mounted and have RF coupling, the M lenses need to be recessed into the camera by 1mm. So with any adapter it would be like adding extension tube to the lens and you can't have infinity focus, only close range focus.
I think that the answer is already her in the thread...
if you notice, the [lens] LTM to M [camera] adapters is approx 1mm thick. this helps adjust the LTM lens outwards by that exact 1mm to the right distance for the rangefinder coupling and the flange distance to the film plane. this need for the rangefinding coupling also implies that it cannot e done the other way around. even if you did machine a [lens] M to LTM [camera] adaptor, the rangefinding coupling will be off. and because of the flange distance is further extended, the lens distance readings will also not be correct.
given that the LTM cameras are all film (no TTL live view), you would not be able to focus properly with it... unless, as gommy put it, you find a "digital screw mount camera". it's not to say it cannot be done.