Can you detail the story of how Sai's portrait, mentioned in Chapter 41, was acquired and delivered?

Certainly. According to Chapter 41, the story begins with Alli Mohammed wandering the streets of Mumbai when he came across a merchant selling pictures of saints and holy men. He was immediately drawn to one particular portrait of Sai Baba, whom he already revered. He purchased the picture, took it home, and hung it on his wall for daily Darshan. The story then connects with the author, who had a dream of Sai promising to visit for a meal on Holi. As described in Chapter 41, at the very peak moment when the author was about to have lunch on that festival day, Alli Mohammed arrived unexpectedly with that same portrait, thus fulfilling Sai's promise in a miraculous way and delighting the author.