I vacation in Maine alot and have been to Maine-ly Stamps in Kittery. I "think" that the one in Arundel is no longer there but I am not positive.
Each time I go, I make sure to go to Maine-ly Stamps. I know she has recently gotten some Copics in stock. She mainly (lol!) has Hero Arts stamps and some others...mostly wood block.
Another MUST have store to hit is Stamped Designs in Dover, NH. It's only about 1/2 hour - 40 minutes from Wells and she has AMAZING product....Copics, TONS of stamps from ALOT of on line companies, papers...it's my favorite place to stop!
Hope this helps and have a great time in Maine!!