Panca-tattva Identities -

What is the basis for seeing Sri Nityananda Prabhu as being in the mood of Ananga Manjari, Sri Advaita Prabhu in the mood of Visakha-sakhi, and Srivasa in the mood of Sri Manjari (as per the Gutika of Siddha Krsna Das Baba)? When and where did these moods first get ascribed to them?

Through their Guru pranalis.

Nitai as Ananga-manjari. Jahnava is understood as Nitai's shakti, and therefore non-different from her. She is connected with Ananta Manjari in Kavi Karnapura's Ganoddesh Dipika (66). Further, it is spelled out for example in Ramai Thakur's Ananga-manjari-samputika:



The text deals with this rather elaborately. With regards to Advaita Prabhu, I would refer you to Advaitadas who is better versed in the texts specific to their parivar. Regarding Srivas Pandit, I don't know of an earlier source for that, but we know from Kavi Karnapura's Chandrodaya Nataka that Mahaprabhu bestowed all his companions a svarUpa befitting for participation in his Vraja-pastimes.

I don't know if there are any guru-praNAlIs traced back to Srivas Pandit though.

In our line there is no distinction made between Sita and Advaita, so her svarupa of Yogamaya reflects on Him too - Paurnamasi. I suppose that goes for Nityananda's line too - Jahnava is confirmed as Ananga Manjari so that goes for Nitai Chand too then.
I remember reading in Siddha Baba's Gutika also that sadhakas in Nitai's line meditate on Lalita's kunj and sadhaka's in Advaita's line on Vishakha's kunj. That is one outside confirmation of Vishakha being Advaita Prabhu.

Though this may be seen as circumstantial evidence, at the end of Vilapa Kusumanjali, verse 99, Raghunatha Das Gosvami offers a prayer to Vishakha but not to Lalita. He was the disciple of Yadunandanacarya, who was in turn a disciple of Advaita Prabhu. Here I see a clear hint that this verse 99 is a hidden prayer to his param guru in Sakhi svarupa, and thus confirmation that Advaita Prabhu is Vishakha. Note also the lengthy Vishakhanandada Stotram in the Stavavali - a praise to delight Visakha.

She is frequently featured in Stavavali in the capacity of a sakhI who is involved with the varieties of services of Raghunath Das Goswami in his svarUpa, suggesting a definite connection there.

I thought Ramananda Raya is Visakha.... or was it Svarupa Damodar?
I mix them up always...

Well, evidently you aren't the only one, since Kavi Karnapura views it one way and Dhyanachandra the other. Dhyanachandra's seems to have become adopted as the common view.

There are several "one in many" cases, please see this post.

Thanks.