I have a 35mm Summicron-M ver 4 (the bokeh king) that I would like to exchange for a 35mm Summarit-M, preferably with the optional shade.

My Summicron is in excellent condition with barely any signs of use. The glass is clear and clean. It has a rear cap and the correct shade, but no cap for the shade (these may be bought if required, but are easily lost). Photos can be supplied to anyone interested.

I guess an exchange would be less messy within the EU - I don't know what the rules for import duty/VAT are for exchanges as opposed to sales.