Costume Shop Finder Milton Keynes Costume Shop Listings page. This section lists as many Costume Shops we could find in Milton Keynes. If you are the owner of a Costume Shop in Milton Keynes please submit your listing using the Get Listed link at the top. These Milton Keynes Costume Shops offer costumes and fancy dress for adults or children in Milton Keynes, including theatrical and party costumes, Halloween costumes and costume accessories. Most Costume Shops listed below also offer costume accessories such as masks, wigs, make up and props in Milton Keynes.