Back from the consultant. Fortunately I have a good spine, and no degeneration that one would typically expect at my age of 46 (he was the same age and said he'd be happy if he had a back as good as mine).
He is happy with the healing and the 10 degrees of kyphosis (spine tilt) isn't 'normal' but it's within tolerances and shouldn't give me much bother when older. I will most likely still get twinges and pain for the rest of my life, but he has said I can exercise properly without worrying too much about pain being an indicator of something wrong. Pop some pain killers and don't do too much was his answer !