Tough luck Ian!
Steve ....I don't know of a way of locking the exposure, other than the half-press on the shutter release.....so you could lock exposure thenpan the camera!
You could use say ....aperture priority, memorise the shutter speed of the first one and use the +/- comp to alter shutter speed if need for subsequent ones.
Post the 3 full size shots to my KK addy ... I'll have a bash for you.