We also did an Alaskan cruise in 2014 and a Norway cruise in 2015. At that time, they were still accepting items to be signed at the front desk (I got photo mattes signed), they just limited the number of 1 or 2 per stateroom. I believe it was in 2016 that they discontinued allowing things to be dropped off at guest services, but you can now carry items with you to get signed when you see the characters.
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