You really need to sort out your uneven floor mate. Then again, I have an idea that will give you even floor performance. Take everything up off the floor and ask someone to create a baseboard on legs for you. When that is done 100%, lay two simple ovals of track down, keep the outer oval away from the edges of the baseboard, and viola. Your model engines will perform more reliably. Don't forget to clean the track with a track rubber properly, all the way round once a month. Ensure you use a cotton bud to clean your engines' driving wheels, as and when. When not in use, put the model engines and rolling stock in their boxes, and cover the entire railway with flexi-cardboard sheets. A very effective way of keeping the dust off.