Hi Steve
I think we drifted off the OP topic a bit
Having bought a lot of second hand "non Runners" over the years
Most of the problems were too much lubrication!!
Oil and solvents(in spray cans) get in where they are not supposed to
softening motor contacts , attacking plastics etc
using a pin or a watchmakers tiny screwdriver to oil parts will only add the smallest amount of lube
but that will be enough to do the job and not spread over the entire layout as a thin film
1 small drop of oil on water will spread a long way for example
keeping oil off the track is important as well as it will cause wheels to lose grip
Hope this helps
Regards Zmil