Trust me, I am a sponge right now. I downloaded the itme you posted, I read all of Dave's site. I want to know all I can about this train so I can have a nice garage display like yours.
So I have an MRC trainpower 6200. It is made for G, but has a power dampner to use with O and HO and metric trains. it's full power is 60VA. in mode one it puts out 0-18.5v DC 35VA max. In mode 2 it goes down to 0-14V DC 27VA Max. Total output is 52VA. It was sold under Bridgewerks, but is MRC.
I appreciate your help greatly. HO is still a new scale for me and I have not dealt with it for almost 25 years. My first train was my dad's Linoel UP from 1962. HO was always so delicate.
I did a quick try with my MRC 6200 and the Schucos and the result was not great. You can probably get the trains to run a scale speed, but unless the tracks are very clean to begin with it will be tough to get them running and to coast through dead spots (once, again for a small loop you might be able to manage). One of the "secrets" of running Schucos is that by all evidence (multiple people testing their transformers) is that the Schuco transformers put out higher voltages than it says in the manual.
Below is a chart I generated about 4 years ago for various transformers including the Schuco, LGB 50081 and MRC 6200. I measure the RMS voltage and the mean as the old Schuco put out a pretty poor DC with a high amount of AC ripple on it where the more modern LGB was pretty pure DC. I measured with No Train (open), with the train running with the wheels spinning but not on the track (no-load -- I couldn't get a rational reading while, and with the wheel stopped (full load). I couldn't get a rational measurement with the train running normally but is is probably about half way between no-load and full load.
What you can see is that the original Schuco put out much higher voltage than the 17V the manual says (this has been confirmed many times by different people). The original transformer also has very high ripple and a high internal resistance (voltage dropping under load).
As you can see from the chart, the LGB is not very far off from the Schuco in terms of the voltage with "no-load" and the "voltage at "full load" when set at 24V. I don't think you will have any problems with the engines running them at 24V for at least a short time, but it will likely shorten the bulb life if you do it all the time.