This is really useful and I will definitely follow this for all my future projects, thanks! I have taken out the boole now, one less element to confuse things, I am still having issues I will check what the Phong is doing to the shape — My c4d document is attached above, thanks for you help
EDIT:
Actually, I haven't tired it with this approach yet — 3 x 5 plane object, make editable.
The file above contains a revision of Igors T shape X 3, I will give this alternative a try and update there post.
Thanks!