To be honest, I'm not deep into toy trains...
I have bought O-scale, HO scale, and N scale at garage sales and other places over the past 20 years.
I bought an HO set recently at a resale store (dead diesel locos) which re-ignited my interest.
I don't have a place to set them up permanently. Although, I'm considering making a setup on an old interior door for maybe the HO or N scale. It would allow a relatively stable surface that could be moved to the attic.
A lot of the stuff I've bought is well used or even broken.
Around 20 years ago I bought a large box of O scale stuff, it contains both Lionel and Marx track pieces, and another time I bought a Lionel New York (Central?) O-scale set. In the first box there were about 6 electric motors and one Lionel steam locomotive shell. I since found out the motors are Marx, I'm not sure if they are repairable.
I am an electronic technician by trade. I worked for Burlington Northern for 2 weeks in 1976 on a crew that replaced ties. My mother was (briefly) a telegrapher for Northern Pacific in the latter 1940s.