It's a trivial matter to swap over the CRT yoke assembly between the two tubes. I've just done this with a Classic II tube put into an SE/30, it works fine. The yoke's held on with a single screw clamp, and can be gently slid off once this is loosened.
That picture looks a little bit like the display I got from one of the Classic II's I've been playing with over the weekend. The power/video connector to the logic board was corroded, causing poor and intermittent contact. In my case, I had to replace the connector with one from another scrap machine because it was so badly corroded - the analog board came from a machine in which the metal chassis was rusted to scrap, and the logic board was destroyed by an exploded battery :'(