Class 57 exhaust panel. This brass kit builds up in three layers. (Main photo) The left hand panel slots through the centre panel (the one with the bolt etches). Which then slots onto the larger panel. Firstly lightly score the back of the etch lines (photo 2) to aid bending these panels. Remove the large panel (filing off all etching tabs) and bend to shape, following the profile of the roof. Then do the same to the bolt head panel. Gently bending this panel to same profile. As this panel is half etched so has no lines on the back. Finally take the top panel. Leaving on the long tabs. Bend to shape and test fit. Then bending the tabs down push through the holes and solder the three etches together from the underside. This completed panel then can be glued to the roof with the edges filled and blending into the plastic body.