My experience of 4 speeds is the tube supporting the gearbox at the back is a V shape, but for a 5 speed it is a U shape with a flat part between the two gearbox mounting plates.
This may be the difference between the TC and the later TCS, but my 72 has a V tube and a 4 speed, and all my 73 and 74s have a U tube and 5 speeds.
The toasted car looks like a U tube supporting the back gearbox mountings.