Hi all, I'm new here and have a few sets handed down to me by my dad. One pre war Lionel with the old style couplers, and two late 40's-early 50's sets. Also an old Marxs (1950's?), a G gauge Lionel "North Pole" set (1989) that I purchased new and an assortment of HO trains and car sets. Over the past few years I noticed my G gauge engine would not stay on the the track. I tinkered with it last year and removed the bottom plate and I think a small spring popped out. Needless to say it no longer runs! I usually use this set around our Christmas tree. Are there any schematics or instructions on how to rebuild these or replace brushes? And addressing the original problem, are there known issues with the tracks for these sets spreading? The other cars seem to hold on the tracks pretty well. Thanks!