Photo 1: I have an extruded product that has plywood plates. I am trying to edit/shape my plate (the extruded blue shape in the photo) to look like the 2D drawing (white shape in the photo). Is there a way I can manually do this?

Photo 1

Photo 2: I need my MDF buildup to be stretched to meet the edge of the rest of the buildup. So far I have tried: 

(1) Stretching the MDF shape -This didn't work because it was stretching the entire thing and wouldn't let me select the side I needed to stretch

(2) Drawing the MDF shape as a polyline, joining it, closing it, and using the SML to assign the MDF layer -This didn't work because it told me my shape needed to be a polyline or a line (even though I drew it as a polyline)

(3) Drawing the MDF shape as a polyline, extruding it, and using the SMA to assign the MDF layer to it -This seemed to work but will I run into any problems by taking that and replacing my current extruded buildup and is this the only solution to get it to "stretch"?

Photo 2