If for nothing else, souvenir shops are known for their lack of customer service and laissez faire attitude.
There is a better option. At the south end of Methoni, where the 2 main roads meet, across the free parking for the visitors of the castle, is your best bet for souvenir shopping. There are numerous choices of keepsakes, ranging from handsome fridge magnets to custom-made cups. I got my cup less than 24 hours after ordering it.
Dimosthenes is always at your service and stays open up to 10.30 PM to serve you better. He is fluent in both English and Greek and patiently and all your questions follower with an array of options that may be suitable for you. There is also that lack of pressure we all hate.
Here’s some contact info. Go visit him at https://www.facebook.com/Deximi.methoni/