This is Vishnu holding Padma, Shankha, Chakra and Gada (Lotus, Conch shell, Discuss and Mace) in his hands. Clockwise starting with the lower right hands. It is the attributes that help us in identifying Hindu deities. Well in most of the cases anyway.
This form of Vishnu, where he is surrounded by the body of Sesha, the seven-headed Cobra, is very specific to Budhanilakantha temple in Nepal. Interestingly one translation of Buddhanilakanta is ‘old blue throat’ and normally it is Shiva who is recognized for the blue throat. . He is also known as Jalakshyan Narayana (Narayana sleeping on water)
This Vigraha is probably a pilgrim bronze. It s about 7 cm in height. There is some oxidation, wear and remnants of worship. This may be dated to the late nineteenth century or early 20th century.
31 Aug 2022: Came across a better example in Dr. Pratapaditya Pal’s book on ‘Nepal Where the Gods are young’ 1975 Page 112 cat item 82. The braiding of the snake is better and that figure is larger about 18 cm. To quote the author ‘ This is the only bronze example of Jalasayana Vishnu from either Nepal or India that has come to light’. Pundole’s auction sold one in their auction on Dec 16, 2014. Well, it may not be unique, but remains a rare Vigraha.