When the original Caledonian Airways merged with British United Airways (OK, really it was a takeover by Caledonian, a bit like a minnow swallowing a whale!), it was called Caledonian // BUA for a few months until it was decided to call it British Caledonian.  Not many aircraft were repainted with these titles, so photo's are not that common.
Ken Fielding
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/kenfielding/6785554123/">Flickr</a>