This is the progress on the wheelchair. It didn't mirror the geometry as I would have liked, I saved a copy of the half chair and in this copy I combined all the objects and it let me mirror. There was a gap down the middle of both pieces, I used Merged Vertex Tool and fixed them all point by point. Yes, very long winded but i wanted to see what it looked like. Next problem is, some parts I didn't want to end up smoothed have been because it is now just one object. Lots to re-do but at least now I have an idea of how the model could look. I shall find out what I've got to do to get it where I want it.