It's a 5x7 Norma Conversion Kit. 5x7 Norma Rear Standard, 5x7 WA Bag Bellows, Regular 5x7 accordion Norma Bellows.
It interchanges with your 4x5 back. You replace the whole back part of the camera.
That bail and back part is not original Norma, it looks homemade to me. Might work with 5x7 holders but beware.
EDIT: Thinking about it some more, you can take part of your 4x5 standard apart, and it will replace the homemade part of the 5x7 rear standard. If in good mechanical shape you should be OK
The 4x5 and 5x7 Norma use the same standard bearer; they are interchangeable.