I also suspect the access to the shutter is from behind and not through the front, but how can one be sure :). I do not know if there is any Mamiya technician available in The Netherlands to be honest - otherwise - I will be giving him a try. I negotiated with the seller and final price on this lens was 200 USD (shipping included) with the issues described (shutter sticks on B and focusing is stiff, but once you move it couple of times it loosens). Do you think it was a reasonable price ?