A Sailor Boy Named Mickey

This particular doll is called the Mickey Doll and is made of vinyl.  They were first introduced in 1956, and manufactured through 1972.  Effanbee Mickey dolls come up on eBay regularly and sell for between $5-50 depending on their condition and type of clothing.  I'm not sure what your relationship with your mother-in-law is, or why she gave it to you-but it's cute!