Decals I get from several sources. Also tried making them , very tricky. Some decals the local sign shop makes , surprising they can make them 1/4 inch tall. And yes tires are everything when it comes to building models. I was always looking at Garage sales , hobby shops to toy shows . I still have over 200 different sizes and styles of tires that I bought over the years. I also still have over 75 steel spoke style wheels from building old fashioned horse drawn models. The tires definately determine the scale of the model. To look correct to the eye everything has to be very close in scale. Unless it is a machine with oversized tires and a lift kit to get that cool look. Thanks again for being very positive with your responses. Much appreciated.