Tutti is one of Barbie's sisters - and had a twin, Todd. They continues being sold in Europe into the 70's and are easily obtainable, especially in played with condition.
I've never heard this version of Tutti being renamed Stacie - Wikipedia is very frequently wrong. Mattel just thought of shifting more dolls and came up with Stacie and later, that horrible Kelly/Shelley thing which seems to have gone out of vogue. Last thing the world need is more baby dolls.