Can you provide details on the author and original publication of Shri Sai Satcharita?

Certainly. The information provided in Chapter 0 identifies the author of Shri Sai Satcharita as the late devotee Shri Govind Raghunath, who was also known as Annasaheb Dabholkar. His work is described as a sweet, inspirational, and grace-filled biography of Shri Sachidanand Samarth Sadguru Sai Baba Maharaj of Shirdi. Chapter 0 also notes its unique publication history: the work was published progressively, chapter by chapter, over a span of six years in the Shri Sai Leela magazine before it was finally completed with a concluding chapter, for which the preface was written.