I pulled apart my Mikado turned 2-8-4 today to cut the little boiler mounting tabs off the frame. When I put it back together, however, the pilot was loose, and there is a gap between the bottom of the frame and top of the pilot. Since it's loose, the cylinders are also now a bit loose. However, I'm pretty sure I didn't lose anything (except it seems I have).
So, the question therefore is what goes in that gap? Can I just shim it with styrene?