Should research service labs accommodate client requests for reformatting their data for publication?
Payment:


Don't do it for free.  Tell him what it will cost and make sure he gives you a valid charge code or prepay (if external) ahead of time.  

To be diplomatic, I would say something like "We can't do this service unless paid and will charge [double whatever you are first thinking].  However as you have the raw data, please feel free to make these edits yourself."  


Ethics/responsibility:  


If you think the data modification and presentation moves you too much to making an analytical inference (and taking responsibility for it)...or for sure if it is in any way "overegging the pudding", then just decline and tell him to do his own presentations. With some diplomatic comment about your center only providing data files and presentation work being responsibility of researchers.  I would also lean this way if you are worried about becoming his "secretary" (having the images sent back and forth for inevitable revisions and further touchups).


People:


He's probably hoping to get you to do extra work for him.  There will always be people who push a bit and who try to get away with what they can.  Just be calm and firm.