Attached a file showing the principles of this methodology. It’s more like subtractive sculpting. just taking shapes and subtracting them from the original block using the “solid tools”. AS Jim D says, it would be better to get photos of the object from more specific/known angles (not arbitrary ones) So you would have a true top, 4 sides and bottom view. These photos can be used (pasted) into a cube as part of the model so you can more acurately verify the building from those same views in sketchup. I think you could achieve the results you want this way with some patience, but a more organic modeler like “Form Z” , modo, or other 3D programs that can show more than one viewpoint at the same time might be better suited to this particular case?
(not sure what version you are running so i have saved the files in SU8 format)
shape8 extended.skp (391.1 KB)