The following is, of course, an opinion:
While a replacement electronic control system will certainly be eventually required when DCS, or key portions of it, are no longer supported, this option will certainly not be feasible for those people with more limited means, primarily financial. Hence, I think in the future there will be a lot of non-working locomotives, primarily Railking, that will be available economically, many if not most of which will have defective [ or non-defective but mis-programmed, etc ] electronics. Running on "conventional " will not be possible for many of these -- but what would be possible would be to strip out all the electronics, leaving just the DC can motors to be wired in series or parallel.
Now, feeding DC onto the track will give the operator direction and throttle control. Horn and whistle would be a fixed 'sound block' or two. Yes, one would have to have some electrical block control for multi-train operation, but an alternate-action on-off pushbutton discreetly mounted on each locomotive would enable it to be isolated independently. The biggest "problem" would be lights, but developing a few standard packages [ diodes, resistors, zeners ] for the different lighting voltages sounds doable without anything expensive or proprietary -- true, it wouldn't be constant lighting, but that's OK under the circumstances.
A person could build a pretty nice and above all economical model railroad -- as distinct from the current [ hah ! ] standard for a toy train layout -- using the above approach.
It's still a great time to be in 0 gauge !
Best, SZ
