Very nice portrait, Richard!
As far as cleaning is concerned, I have always cleaned my own sensor, and having tried most available options, I find wet cleaning to be the most effective. I have been using for the last few years sensor swabs plus, premoistened and individually packed. Otherwise, I use a blower bulb in between cleanings.
M cameras usually have an oil splatter problem from the shutter for the first couple of thousand shots. Beyond that a wet cleaning 3 times a year is enough.