I read something about a portrait of Sai Baba being involved when H.S. Dixit was planning his first trip. What's the story behind that?

Yes, a significant event involving a portrait of Sai Baba occurred right after H.S. Dixit's travel plans were finalized. According to Chapter 51, after Dixit and Madhavrao Deshpande decided to take the ten o'clock night train to Shirdi, Balasaheb Mirikar revealed a special photograph of Baba. This portrait originally belonged to Megha, a devoted disciple who worshipped it as Lord Shankar. The glass on the portrait had broken, so it was sent from Shirdi with Balasaheb to be repaired in Nagar. The repaired portrait was kept covered in Mirikar's drawing room and was entrusted to Madhavrao to take back to Shirdi, creating a beautiful coincidence where Dixit would be accompanied not just by a guide, but also by Baba's image on his very first journey.