The dovetails are nice and tight but they are not pushed completely home so only stuck in one direction. So that is part of the reason for it being out of square. Serves me right for trying to do a glue up late at night just before leaving the workshop.

Although because I made such a poor job of it I may now be able to save it! I am contemplating the best course of action might be to cut the top from the box as I would have done so originally anyway and then attempt to ease it apart the joints using either meths or heat (obviously not at the same time). That will make it easier to keep the padouk out of danger. I wonder if a paint stripper heat gun (you know one of those electric hairdryer style heat guns), that some one gave to me, might do the job as when you use pva in veneering you let it dry completely and reactivate the adhesive a hot iron.
It is better not to mess things up in the first place than to have to spend an inordinate amount of time trying to correct the problems afterwards, but up the side, I am unlikely to try and glue up a project in a hurry again. I had hoped that an antiques restorer or cabinet maker might have immediately known what to use. Afterall I cannot be the first person to have done something this daft.
Well I will report back when I have plucked up the courage to tackle it. I have been avoiding looking at the box for the past week carrying on with other projects as though it doesn't exist, but I cannot ignore it for much longer. I am also going to glue up a few pieces of stock as suggested and try and separate them after a few days using the various ideas.