after lofting it should keep a history(any changes to consruction lines will remake loft)
selecting the solid and clicking on "Show pts." to move the points up - but show pts. isn't working -> Show pts for works for faces (detached from solids)
selecting the 30 mm long upper edge, trying to drag this up - doesn't move -> try to select face & extrude
selecting the 30x20 face, try using the 1d and 2d scaling tools selecting the base as center, trying to scale the face - nothing happens -> detach face if u want so, rework with particular face

The only way how I could manipulate the solid was to use scale on the entire solid -> scale2d/booleans, remake construction line & extrude