Thanks Larry, I think the cleaning did the trick as no power loss now.  Some of the goo I removed from the wheels (presumably a build up since 1948!) was almost like the wheels had a rubberized coating. I know rubber does not conduct electricity!  The rollers had some crud too. I would surmise that some of this could be oily buildup mixed with charged particles/dust.  I have never oiled anything but the engine in the weep hole on the bottom and only twice since I've had the train (since 1970), but I am guessing over time someone may have oiled the axles thinking it needed it.  Do they?  Thanks again.  Ken