Prior to the writing of the Sai Satcharitra, were there other books or poems that documented the stories of Sai Baba, and if so, can you name them?

Yes, Chapter 2 confirms that several works about Sai Baba already existed. The author mentions that the esteemed Das Ganu had already described Shri Sai's life across three chapters in his book titled Bhakta-Lilamrut. Furthermore, a specific story told by Sai is documented in Chapter 57 of Das Ganu's Santa-Kathamrut. As Chapter 2 details, other sources included Raghunath-Savitri’s Bhajanmala, various poems by Das Ganu, and writings specifically for Gujarati devotees by Amidas and Bhavani Metha. There was also a series of stories being published in Pune under the name Sai Prabha.