Four Mirror One puzzle by Osanori Yamamoto

This is a fantastic puzzle!
It's not too easy, nor is it too hard to solve. It comes from the mind of a brilliant Japanese puzzle inventor called Osanori Yamamoto, whose Bisect Cube puzzle was one of the first things I uploaded to Thingiverse.
Not only are all his designs very clever puzzles, but many of them are also ideally suited to 3D printing as they require no additional support.
The puzzle consists of one ring shaped piece and four identical T pieces. These must be assembled with the