This is my first attempt at 3D model compositing.
I'm quite pleased with the result, it's not perfect and I will get better but it at least looks how I imagined it would.
The model was made in LeoCAD and exported to Blender to be rendered with the shadow. The background image was adjusted in GIMP before going into fSpy to act as a Blender camera reference. The model was lined up in Blender and after being rendered the image was taken back into GIMP to be overlaid and composited with the background photo.
To think all this was learned in about 4 weeks and all achieved with free software is quite mind-blowing, even for me. I have lots of ideas now that the method is nailed down.
Staying in just became a lot more fun.